Question

Challenge question: Solve for 7 and check.-a + 7 = 11

Answer 1

This problem is about a linear equation, where its variable is a.

First, we need to subtract each side of the equation by 7-

$-a+7-7=11-7$$-a=4$

Now, we need to multiply the equation by -1, to have the variable positive

$-a(-1)=4(-1)$$a=-4$

Once we have the value of the variable, we can check if the answer is right. To do that, we just need to substitute this value in the given equation.

$-a+7=11$$-(-4)+7=11$$4+7=11\text{ }\rightarrow\text{ 11=11}$

As you can observe, the answer satisfies the equation.

Therefore, the right answer is -4.