Using the linear combination method, what is the solution to the system of linear equations 7 x minus 2 y = negative 20 and 9 x + 4 y = negative 6?

(- 2, 3 )

Step-by-step explanation:

Given the 2 equations

7x - 2y = - 20 → (1)

9x + 4y = - 6 → (2)

Multiplying (1) by 2 and adding to (2) will eliminate the term in y

14x - 4y = - 40 → (3)

Add (2) and (3) term by term to eliminate the term in y

23x = - 46 ( divide both sides by 23 )

x = - 2

Substitute x = - 2 into either of the 2 equations and evaluate for y

Substituting into (2)

9(- 2) + 4y = - 6

- 18 + 4y = - 6 ( add 18 to both sides )

4y = 12 ( divide both sides by 4 )

y = 3

Solution is (- 2, 3 )

use formula for the circle a=3.14

step-by-step explanation:

36 girls

step-by-step explanation:

the 48 boys is 4 parts of the ratio

divide 48 by 4 to obtain one part of the ratio

= 12 ← 1 part of the ratio

3 parts = 3 × 12 = 36 ← number of girls