Question

Use elimination method, substitution method
and cross 3x-4÷7y=8 and 2x+3y=-3​

Answer 1

Step-by-step explanation:

by substitution method

3x-4÷7y=8 - (1)

2x+3y=-3 -(2)

3x-4= 56y

3x-56y=4 -(1) × 2

2x+3y=-3 -(2) ×3

6x-112y= 8

6x+9y =-9

-121y= 17

y= -17/121

now putting the value of y in equation 2

2x+3y= -3

2x+3×-17/121=-3

2x-51/121=-3

242x-51= -363

242x=-312

x = -312/242.

by elimination method

2x+3y = -3

2x = -3-3y

3x-4 = 56y -(1)

putting the value of x in equation 1

3×(-3-3y÷2)-4 =56y

(-9-9y÷2)-4= 56y

-17-9y= 112y

-17=121y

y= -17/121

now putting the value of x

2x+3y =-3

2x+3×-17/121=-3

2x-51/121=-3

242x-51=-363

242x = -312

x= -312/242.

it is a right answer.