Solve by elimination.. SHOW YOUR WORK. -3x + 2y = 18
-9x - 5y=21

x = —4, y = 3

Step-by-step explanation:

-3x + 2y = 18 (1)

-9x - 5y =21 (2)

To solve by eliminating, the coefficients of either x or y must be the same in both equation.

Now let us make the coefficient of x in both equation to be the same. To do this, multiply equation (1) by the coefficient of x in equation (2) ie —9, and multiply equation (2) by the coefficient of x in equation (1) ie —3 this is illustrated below :

—9 ( —3x + 2y = 18)

27x — 18y = — 162 (3)

—3 ( —9x — 5y = 21)

27x + 15y = —63 (4)

Now, subtract equation 4 from equation 3

27x — 18y = — 162

— (27x + 15y = —63)

—33y = —99

Divide both side by —33

y = —99/—33

y = 3

Now we substitute the value of y into any of the equation to obtain x. In this case, let use equation 4

27x + 15y = —63

27x + 15(3) = —63

27x + 45 = —63

Collect like terms

27x = —63 —45

27x = —108

Divide both side by 27

x = —108/27

x = —4

Therefore, x = —4, y = 3

a - base

b - exponent

so,

8

step-by-step explanation: