The change is given by the difference between how much you paid and how much you actually had to pay. For example, if you pay with a $50 bill and you had to pay $13, your change will be
dollars.
In this case, we have

So, Gabriel's mistake was to leave the negative sign to the "-2" at the end of the expression, instead of flipping it to positive "+2" when subtracting it.
Answer:
3x + 7
Step-by-step explanation:
<u>Step 1: Distribute the plus</u>
(x + 4) + (2x + 3)
x + 4 + 2x + 3
<u>Step 2: Combine like terms</u>
x <u>+ 4</u> + 2x <u>+ 3</u>
<em>3x + 7</em>
<em />
Answer: 3x + 7
<u>If needed solve</u>
3x + 7 - 7 = 0 - 7
3x / 3 = -7 / 3
<em>x = -7/3</em>
A triangle with 2 congruent sides is an <u>ISOSCELES</u> triangle.
Answer: Isosceles
FYI: A triangle with 3 congruent sides is an equilateral triangle.
3^-4 = 1/3^4 = 1/81
hope it helps!