Question

how to solve 2x+y=7 and 6x-5y=45 using substitution

Answer 1

Answer:

Step-by-step explanation:

Two equations are given as below:

3x + 5y = 9 …Eq. 1

5x + 3y = 7 …Eq..2

In order to solve, multiplying Eq…1 with 5 and Eq..2 with 3

15x + 25y = 45

15x = 45 - 25y…Eq..3

Now substituting value of 15x from Eq..3 to Eq..4 as following

15x + 9y = 21…Eq…4

45 - 25y + 9y = 21

—16y = 21 - 45

--16y = —24

y = 24/16

y = 3/2

Substituting the value of y in Eq..1

3x + 5 (3/2) = 9

3x + 15/2 = 9

3x = 9 – 15/2

3x = (18 - 15)/2

3x = 3/2

x = 3/2 × 1/3

x =1/2

Now calculating the value of x + y

x + y = 3/2 + 1/2

x + y = 4/2

x + y = 2