Answer:
The student is not correct. He should use parentheses like this 9(n+13). Without the parentheses, it means nine times n plus 13, but should be the sum of n plus 13 multiplied by 9.
7.) 170
8.) 9
9.) 44
10.) -124
11.) -99
12.) 84
13.) 88
14.) -1080
15.) -27
16.) -81
17.) -27
18.) -81
Answer:
C 7 times 5 plus 7 times 4 is the answer
1 + (-5) becomes 1 - 5 because you are adding a negative number.
1 - 5 is -4
For the perimeter you have to consider the EXTERNAL SHAPE ONLY:
a) the perimeter of half a circle WITHOUT ITS DIAMETER is:
π.R - 2R → 3.14x1.5 - 2x1.5 → 1.71 cm
b) the perimeter of the rectangle WITHOUT THE UPPER SIDE is:
2.5+3+2.5 = 8 cm
Hence the perimeter of the figure is 1.71 + 8 = 9.71 cm
2) Area of the figure:
Area of half circle is π.R²/2 →3.14 x (1.5)²/2 → Area half circle = 3.5325 cm²
Area of rectangle = 2.5 x 3 = 7.5 cm²
Total area = 3.5325 + 7.5 = 11.0325 ≈ 11 cm²