Finding the Value of a Linear Expression
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If $7x + 21 = -2$, what is the value of $x + 3$ ?
A) $-5$
B) $-2$
C) $-\frac{5}{7}$
D) $-\frac{2}{7}$
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Step by Step Written Solution
In this problem, we are given a linear equation and asked to find the value of a specific expression. Let's look at the equation seven x plus twenty-one equals negative two.
Given Equation
We could solve for x directly and then substitute it back, but there's a much faster way. Notice that the expression on the left side can be factored.
The terms seven x and twenty-one share a common factor of seven.
Look closely at what we have inside the parentheses. It's exactly the expression 'x plus three' that the question is asking us to find!
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