Answer:
14,28,42 and 56
Step-by-step explanation:
Multiply all lengths by 2 as the quadrilateral is dilated by a scale factor of 2
If x=girls,
then we have 3x boys.
We know that all children are boys+girls, so x+3x, which is 4x and 4x is 48, so one x is 12.
So there are 12 girls and 36 boys.
We have this equation:

So, we need to solve this equation for L. Then we sum -2W in each member of the equation, like this:


Then, dividing the equation by 2:

Finally, let's order this equation:
Answer:
0.16 π
Step-by-step explanation:
Using the area formula pi*r^2 we can find the area of the circle, plugging in the numbers gets us pi*(0.4)^2 = 0.16 π
Answer:
Dave is 18 and his sister is 6.
Step-by-step explanation:
If you do 38 -7x2 you can work out the combined ages of them now which is 24 (you have to do 7x2 because there are two of them and its seven years in the future). Then you can work out their ages using a ratio. Dave’s age : his sister’s age is 3:1 so if you divide 24 by 4 (3+1 = 4 so your can work out one portion of their age) you can find out how old the sister is which is 6. Times that by 3 to get Dave’s age which is 18. A formula for this (where x is his sisters age) would be 3x=38-7x2 which cancels down to 6.