Question

Kevin is solving the system of equations below using linear combination. Fill in the blanks for each question. Do not type any words or spaces. 2x - y = 10 4x - y = 5 1. What should Kevin multiply by if he wants to eliminate the y terms? 2. What should he multiply by if he wants to eliminate the x terms?

Answer 1

We have two system of equations

2x - y = 10

4x - y = 5

This system of equations can be solve simultaneously using the elimination method.

For Kelvin to eliminate y, he needs to multiply both equation by 1 because the both have the same co- efficient

Therefore, the wquation becomes

2x * 1 - y*1 = 10* 1 ------

4x * 1 - y *1 = 5 * 1

2x - y = 10

4x - y = 10

For Kelvin to eliminate x, he needs to multiply equation 1 by 2 and equation 2 by 1. This is because the co-efficient of x in the second equation doubles the co-efficient of x in the first equation.

Therefore,

2x * 2 - 2 *y = 10*2

4x * 1 - 1* y = 5 * 1

4x - 2y = 20