To find how long it would take him, one has to divide 400 by 160 and then multiply 5 by what that number is. You multiply 5 by the quotient because that is the number that would make it proportional. 400/160 x 5 is 12.5, meaning that the answer is 12.5 minutes, or A.
Writing an equation is the easiest way to figure this out.
b = boys, g = girlsb = 3/4g35 students = g + b35 = g + 3/4g35 = 7/4g35/7/4 = g20 girls35 - 20 = b or 3/4(35) = b15 boys
Answer:
-150
Step-by-step explanation:
x^2 - 7x^2 - 18x +42
3^2 - 7(3)^2 - 18(3) + 42
9 - 63 - 54 + 42
-54 -54 + 42
-108 + 42
-150
Answer:
8m ×3.5m
Step-by-step explanation:
Area of rectangle= length ×width
Let the length and width of the rectangle be L and W meters respectively.
Area of rectangle= LW
LW= 28 -----(1)
L= 2W +1 -----(2)
Subst. (2) into (1):
(2W +1)(W)= 28
<em>Expand:</em>
2W² +W= 28
<em>-28 on both sides:</em>
2W² +W -28= 0
<em>Factorise</em><em>:</em>
(W +4)(2W -7)= 0
W +4=0 or 2W -7=0
W= -4 (reject) or W= 3.5
Substitute W= 3.5 into (2):
L= 2(3.5) +1
L= 7 +1
L= 8
∴ The dimensions of the rectangle is 8m ×3.5m.
