36.1k views
1 vote
Solving systems elimination: I don’t understand how to solve at all. Please help if you can.

Solving systems elimination: I don’t understand how to solve at all. Please help if-example-1
User Qvpham
by
7.8k points

1 Answer

3 votes

The solution to given system of equations y = 3x - 9 and y = -2x + 16 are (x, y) = (5, 6)

The solution to given system of equations y = 5x + 22 and -6x - 4y = -10 are (x, y) = (-3, 7)

Solution:

Given that, we have to solve each system by substitution method

Given system of equations are:

y = 3x - 9 ----------- eqn 1

y = -2x + 16 -------- eqn 2

Substitution method is done by substituting eqn 2 in eqn 1

Substitute the value of "y" from eqn 2 into eqn 1

-2x + 16 = 3x - 9

Move the variables to one side and constants to other side

-2x - 3x = -9 - 16

Combine the like terms

-5x = -25

Cancel the negative sign on both sides of equation

5x = 25


x = (25)/(5) = 5

x = 5

Substitute x = 5 in eqn 1

y = 3(5) - 9

y = 15 - 9

y = 6

Thus solution to given system of equations are (x, y) = (5, 6)

Given another system of equations are:

y = 5x + 22 ----- eqn 1

-6x - 4y = -10 ------ eqn 2

Substitute eqn 1 in eqn 2

-6x - 4(5x + 22) = -10

-6x - 20x - 88 = -10

Move the variables to one side and constants to other side

-26x = -10 + 88

-26x = 78

x = -3

Substitute x = -3 in eqn 1

y = 5( - 3) + 22

y = -15 + 22

y = 7

Thus solution to given system of equations are (x, y) = (-3, 7)

User Pioupiou
by
9.2k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories