Question

Solve the following equations express your answers as order pair in format a,b 2x+7y=-1 and 4x-3y=-19

Answer 1

Answer:

(x , y) = ( -4 , 1)

Step-by-step explanation:

2x + 7y = -1 --------eqn 1

4x - 3y = -19 ----------eqn 2

Step 1: let's pick eqn 1, to make y the subject of the formula

2x + 7y = -1

7y = -1 - 2x

Divide both sides by 7, to make y the subject of the formula

7y/7 = (-1 - 2x)/7

y = (-1 - 2x) / 7

Step 2: substitute y into the equation 2

4x - 3y = -19

4x - 3(-1 - 2x)/7 = -19

Open the bracket

-3 * -1 = +3

-3 * -2x = +6x

4x +( 3 + 6x)/7 = -19

LCM = 7

(28x + 3 + 6x)/7 = -19

(34x + 3)/7 = -19

Cross multiply

34x + 3 = 7 * -19

34x + 3 = -133

34x = -133 - 3

34x = -136

Divide both sides by 34,to get the value of x

34x/34 = -136/34

x = -4

Step 3: substitute x = -4 into eqn 1

2x + 7y = -1

2(-4) + 7y = -1

-8 + 7y = -1

7y = -1 + 8

7y = 7

Divide both sides by 7, to the value of y

7y/7 = 7/7

y = 1

(x , y) = ( -4 , 1)