Question

Solve the system with elimination.
-2x + 7y =10
x - 3y = -3

Answer 1

x = 9 and y = 4

Explanation:

-2x + 7y = 10 (call this equation '1')

x - 3y = -3 (call this '2')

multiply '2' by 2:

2x - 6y = -6 (call this '3')

add '1' and '3':

(-2x + 7y = 10) + (2x - 6y = -6)

0x + y = 4

y = 4

sub that back into '1':

-2x + 7y = 10

-2x + 7(4) = 10

-2x + 28 = 10

-2x = 10 - 28 = -18

x = -18/-2 = 9

sub both y = 4 and x =9 into '2' to check if everything adds up:

x - 3y = -3

9 - 3(4) = 9 - 12 = -3

so x = 9 and y = 4