Answer:
a. 32
b. 48
Step-by-step explanation:
Forty percent of the 80 birds were robins.
a. How many of the birds were robins?
b. How many of the birds were not robins?
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Forty percent of the 80 birds that were robins = 40%/100%
To find how many of the birds were robins, use part/whole = part/whole
40%/100% = ?/80
This will tell us how many exact robins were there
To solve, multiply 80 by 40 and then divide all by 100
80 x 40 ÷ 100 = 32
so 32 of the birds were robins
now for b since 32 of the birds were robins out of 80 birds, subtract 32 from 80.
80 - 32 = 48
Answer:
5 : 30
Step-by-step explanation:
Note that
× 10 = 5
Thus 3 × 10 = 30
Hence
: 3 = 5 : 30
Answer:
The ratio of perimeter of ABCD to perimeter of WXYZ = 
Step-by-step explanation:
First, we have to determine the multiplicative factor of the dimensions for both figures.
Considering sides AB and WX,
multiplicative factor = 
= 1.5
So that:
XY = 6 x 1.5 = 9
YZ = 7 x 1.5 = 10.5
ZW = 7 x 1.5 = 10.5
Perimeter of ABCD = 6 + 7 + 7 + 8
= 28
Perimeter of WXYZ = 9 + 10.5 + 10.5 + 12
= 42
The ratio of the perimeters of the two quadrilaterals can be determined as;
ratio = 
= 
= 
The ratio of the perimeter of ABCD to perimeter of WXYZ is
.
F(x)= -8x²
f(-3)= -8* (-3)²
f(-3)= -8 * 9
f(-3)= -72