Question

A student is trying to solve the system of two equations given below: Equation P: a + b = 6 Equation Q: 4a + 2b = 19 Which of the following steps can be used to eliminate the a term? −1(4a + 2b = 19) −4(4a + 2b = 19) −4(a + b = 6) 4(a + b = 6)

Answer 1

Answer:

$-4(a + b = 6)$

Step-by-step explanation:

Given

$a + b = 6$

$4a + 2b = 19$

Required

Eliminate a

Multiply the first equation by -4

$-4(a + b = 6)$

Add to the second equation

$-4(a + b = 6) + (4a + 2b = 19)$

Solve brackets

$(-4a -4b = -24) + (4a + 2b = 19)$

Open bracket

$-4a + 4a -4b + 2b = -24 + 19$

$-4b + 2b = -24 + 19$

At this point, a has been eliminated;

From the list of given options, the option that answers the question is $-4(a + b = 6)$