Question

Use substitution to solve the system of equations.
http://prntscr.com/b4wbah Could someone please give me the answer and explain how they got it? I just don't understand. I'd truly like to grasp it ((:

Answer 1

Pick one of the equations and solve for one of the variables. Then substitute what you got for the variable (should be an expression) as the variable in the other equation and solve. Substitute what you get into one of the equations to solve for the other missing variable.

Answer 2

You should get x = 9, y = -1.

Answer 3

so there are

3x - 3y =30 => 3(x-y)=3*10 divide both sides by 3 and will get x-y=10
-2x +8y = -26 => -2(x-4y) = -2*13 divide both sides by -2 and get x-4y=13

x-y=10 => x = y+10 so using substitution method just substitute this value of x inside second equation in place of x and will get
x-4y=13

y+10 -4y =13
-3y = 3
y = 3/(-3) = -1

y = -1

but we know that x = y+10 so x = -1 +10 so x = 9

x = 9
y = -1 from these result that choice B. is right sure

hope these are understandably sure right easy for you

was my pleasure

good luck