Question

solve the simultaneous equation 2x-5y=-11;3x+3y=15​

Answer 1

Answer:

y=3 x=2

Step-by-step explanation:

(2x-5y=-11)*(-3)=-6x+15y=33

(3x+3y=15)*2=6x+6y=30

(-6x+15y=33)+(6x+6y=30)=(21y=63)

y=63/21=3

y=3

3x+3*3=15

3x=15-9

x=6/3=2

x=2

Answer 2

Answer:

x = 2, y = 3

Step-by-step explanation:

This will be done using the substitution method.

2x-5y = -11 -------------- EQUATION 1

2x = -11+5y

x = $\frac{-11+5y}{2}$

3x+3y = 15 --------------- EQUATION 2

Substitute E1 into E2:

3x+3y = 15

3 ($\frac{-11+5y}{2}$) +3y = 15

Multiply each number by 2 to eliminate the denominator, 2 from the fraction.

3(-11+5y) +6y = 30

-33+15y+6y = 30

21y = 63

y = 3

Substitute y = 3 into E1:

2x-5(3) = -11

2x-15 = -11

2x = 4

x = 2