You can set up a proportion that looks like 3/7 = x/21. X being the number that you are trying to find. Seven goes into 21 three times. So multiply 3 also by that 3 to get 9. So three sevenths of twenty-one is 9.
Answer:
10 square in.
Step-by-step explanation:
The rectangles are similar by a scale factor of 3. We can tell because the quotient of two of the corresponding sides, 18 and 6, is 3 (18/6=3)
That means the width of ABCD is 3 times the width of WXYZ.
Let's say the width of ABCD is x. Then 18*x=90 because that's the area.
x=90/18=5
Now we have the width of ABCD, 5, so to get the width of WXYZ, we divide by 3, which is 5/3.
Now to get the area of WXYZ, we can do 5/3, the width, times 6, the length, which is 30/3=10.
Answer:
a 30 b -21
Step-by-step explanation:
a 5x = 5(6)
= 30
b 3y = 3(-7)
= -21
