Want to join the conversation? The answer to is: Solve the second equation. Gauth Tutor Solution. Which equation is correctly rewritten to solve for x talk. So if I make this a 35, and if I make this a negative 35, then I'm going to be all set. Solve equation 2 for y: Substitute into equation 1: If equation 1 was solved for a variable and then substituted into the second equation a similar result would be found. And the reason why I'm doing that is so this becomes a negative 35. He could have just used a 5 instead of a -5, but then he would have had to subtract the equations instead of adding them.
So the point of intersection of this right here is both x and y are going to be equal to 5/4. How would you figure out what x and y are if the equation cancels both out. And I can multiply this bottom equation by negative 5. Negative 10y is equal to 15.
You divide 7 by 7, you get 1. And what do you get? We're going to have to massage the equations a little bit in order to prepare them for elimination. And now, we're ready to do our elimination. Use the substitution method to solve for the solution set.
Crop a question and search for answer. But even a more fun thing to do is I can try to get both of them to be their least common multiple. Ask a live tutor for help now. Which equation is correctly rewritten to solve for x 2 0. Simplify the left side. Qx + p -p = r -p. The equation becomes. And so what I need to do is massage one or both of these equations in a way that these guys have the same coefficients, or their coefficients are the negatives of each other, so that when I add the left-hand sides, they're going to eliminate each other.
When finding how many solutions an equation has you need to look at the constants and coefficients. Otherwise, substitution and elimination are your best options. Raise to the power of. Good Question ( 172). Mye, He used a negative 5 so he could just add the two equations and the 10y and -10y become 0y and eliminate the y. These aren't in any way kind of have the same coefficient or the negative of their coefficient. Which equation is correctly rewritten to solve for x? -qx+p=r - Brainly.com. That would work the same way and you get the same answer. Therefore, is not valid. Sal chose to multiply both sides of the bottom equation by -5. When you add -6x - 4y = -36 and 6x + 4y = 8, you get 0 on the left side of the equation and -28 on the right side. These guys cancel out. How can you determine which number to multiply by? And if you subtracted, that wouldn't eliminate any variables. All Algebra 1 Resources.
Apply the power rule and multiply exponents,. So let's pick a variable to eliminate. So we can substitute either into one of these equations, or into one of the original equations. In some cases, we need to slightly manipulate a system of equations before we can solve it using the elimination method.
And that's going to be equal to 5, is the same thing as 20/4. And if you take 5 times 5/4, plus 7 times 5/4, what do you get? That is, these are the values of that will cause the equation to be undefined. Divide both sides by 64, and you get y is equal to 80/64.
You know the second equation couldn't he just multiply that by 5x? So this does indeed satisfy both equations. So these cancel out and you're left with x is equal to-- Here, if you divide 35 by 7, you get 5. The terms can be eliminated. Which equation is correctly rewritten to solve for x 3 0. Use the power rule to combine exponents. Now, we can start with this top equation and add the same thing to both sides, where that same thing is negative 25, which is also equal to this expression. That is why he had to make the numbers negative in order to cancel them out. Solve the equation: Notice that the end value is a negative.
Divide each term in by. Sal chose to make each step explicit to avoid losing people. That was the whole point. Is going to be equal to-- 15 minus 15 is 0. Adding a -15 is like subtracting a +15. On the left hand side of the equation, the q numerator will cancel the q denominator, leaving us with only x). Let's substitute into the second of the original equations, where we had 7x minus 3y is equal to 5. Which equation is correctly rewritten to solve for - Gauthmath. You have to get it so either the x or the y are opposite co-efficients because say you have 5x-y=8 and -6x+y=3 you have to eliminate the y and you would get -1x=11.
So we get 7x minus 3 times y, times 5/4, is equal to 5. Do the answers multiply back to the original if factored? But I'm going to choose to eliminate the x's first. So you multiply the left-hand side by negative 5, and multiply the right-hand side by negative 5.
Cancel the common factor. Created by Sal Khan. We can multiply both sides by 1/7, or we could divide both sides by 7, same thing. 64y is equal to 105 minus 25 is equal to 80. Remember, my point is I want to eliminate the x's. So if you looked at it as a graph, it'd be 5/4 comma 5/4. I could get both of these to 35. Let's say we have 5x plus 7y is equal to 15. Because if this is a positive 10y, it'll cancel out when I add the left-hand sides of this equation.