How do you solve,
3x - 4y = -31
-3x - 3y = -18

(- 1, 7 )

Step-by-step explanation:

Given the 2 equations

3x - 4y = - 31 → (1)

- 3x - 3y = - 18 → (2)

Adding the 2 equations term by term will eliminate x, that is

0 - 7y = - 49

- 7y = - 49 ( divide both sides by - 7 )

y = 7

Substitute y = 7 into either of the 2 equations and solve for x

Substituting into (1)

3x - 4(7) = - 31

3x - 28 = - 31 ( add 28 to both sides )

3x = - 3 ( divide both sides by 3 )

x = - 1

solution is (- 1, 7 )

1) c 2143.6 cm

2) c 113.0 m

3) a 33.5 ft

4)   d 2 cm

5) c 20 mm

6) 180 in

7) d 120 ft

e.

step-by-step explanation:

because there are always 10 numbers in a phone number.