When mary was born, she weight 8 pounds. when she was 10, she weighed 10 times as much. write and solve an equation to find the difference between mary's weight when she was 10 and when she was born.

Δw = * 10 - = 72 pounds

Step-by-step explanation:

Using the names

: weight when born

:weight when she was then

Δw: weight difference

the equation would be

Δw = -

since

= * 10

we can replace and we have that

Δw = * 10 -

and since

= 8

Δw = 8 * 10 - 8 = 72

i did it myself and i got 4.2 (b) hope its right

step-by-step explanation:

we have three similar triangles, because each has a right angle and shares an angle.   let's write the angles in order: opposite to short leg, long leg, hypotenuse.

cab similar to bad similar to cbd

or as ratios,

ca: ab: cb = ba: ad: bd = cb: bd: cd

we also know

ac = ad + cd

(ad+cd): ab: cb = ba: ad: bd = cb: bd: cd

(ad+cd)/cb=cb/cd

we have cb=6, ad=5 and seek x=cd.

we reject the negative root and conclude x=4

answer: 4