Solve for x and y
3x-7y=6

7x+3y=72

This is a System of Equations, so basically what we want to do is to get one of these variables to equal zero. However none of the variables are equal, 7x doesn't equal 3x and 3y is not 7y. So we need to multiply both equations in the system to make one of these variables equal.

Let's Multiply The Top One By 3

Let's Multiply The Bottom One By 7

Now As You Can See 21y and -21y are equal, aand by that I mean that they will equal zero once added.

Now We Solve The System
1st. Add Straight Down Ex. 9x+49x, -21y+21y, 18+504

Add Straight Down

Now we Solve For X


Now We've Found X, We Need Y, and We Can Find It By Plugging In X To One of The ORIGINAL EQUATIONS.

One Of The Original Equations


1st. X=9, So Replace X with 9


Solve For Y



Now We Test It, X=9, Y=3

AND


SO: ANSWER

Look, when you want to do something like put it like x^2. x2 could mean x² or x₂. so to clear confusion, know the notation. to find the product multiply the x's and you get -8x and the y's and you get 6y. since it's all being multiplied it is just -8x6y, or answer a. although the better answer is -48xy(combining -8 and 6) because you should multiply constants whenever you can.