4.16 10^8
Hope this helps *smiles*
first you turn the fractions into inproper fractions by multiplying the whole number by the denomonator and adding the numerator
4×4=16
16+3=19
19/4
4×7=28
28+1=29
29/7
keep the denomonators the same. now that you've converted them into inproper fractions you can multiply them
19/4 × 29/7=551/28
there is no way to simplify this answer so this is the final answer
Again, nice problem. These are not super easy. You need to imagine the triangles in the figure and relate sides.
For instance: ADC, its hypotenuse is 15
For ABC, it is 20,
so 20/15 is the ratio between both triangles. Now let's choose the side with 'x'
x is one side of ADC, the corresponding side in ABC is 15 (the second longest sides). You need to rotate the triangles, etc ... That's the tricky part :)
So:
20/15 =15/x ----> x = 15*15/20 = 225/20 = 45/4
Which is C
Not sure whether it's too late to help you though!!!!
Also notice that it's kind of a product rule:
x * 20 = 15 * 15
I am sure the book explains a short way of getting to this equation, like sides opposite, blah blah, but what i told you is the reason. You asked for understanding it! Best luck!
