Question

Justify each statement with a property from algebra or property of congruence.

If $2x+y=70$and $y=3x$then $2x+3x=70$.

Short answer

From theproperty of Algebra, it is proved that$2x+3x=70$.

Step-by-step solution

Step 1. Apply substitution property of algebra.

The substitution property of equality states that if $x=y$, then x can be substituted in for y in any equation, and y can be substituted for x in any equation.

Step 2. Description of step.

Substitute $3x$ for y into the equation $2x+y=70$.

$\begin{array}{c}2x+y=70\\ 2x+3x=70\end{array}$

Step 3. Description of step.

Simplify the equation mentioned in step 2.

$2x+3x=70$

Therefore, the value of$2x+3x$is 70.