Solving a System of Equations Using Linear Combination
What is the solution to this system of equations?
4x + 5y = 7
3x - 2y = -12
Multiply each equation by a number that produces opposite
coefficients for x or y.
The solution is
|(-2,3)
1(3,-1)
(7,3)
|(13,-9)

Solution:

Given system of equations are:

4x + 5y = 7 eqn 1

3x -2y = -12 eqn 2

Multiply eqn 1 by 2

8x + 10y = 14 eqn 3

Multiply eqn 2 by 5

15x - 10y = -60 eqn 4

Add eqn 3 and eqn 4

8x + 10y = 14

15x - 10y = -60

( + )

23x = -46

Substitute x = -2 in eqn 1

4(-2) + 5y = 7

-8 + 5y = 7

5y = 15

Thus the solution is (x, y) = (-2, 3)

step-by-step explanation:

answers available in this download

(pearson%2c%25202012)%2520bbs.pdf& usg=aovvaw1obmtxnfghfgxhx0urh_je

i think it is 70

step-by-step explanation: