to solve for j first you need to cross multiply;
j × 35 = 42 × 55
35j = 2,310
j = 2,310 ÷ 35 (did the inverse operation)
j = 66
Hope that helps :D
That would simplify to 32x^5+400x^4+200x^3+5000x^2+6250x+3125
You would do that because you have to write it repeatedly as (2x+5)(2x+5) and so on.
Let f be the height of the fir trees
Let p be the height of the pine trees
We know from the problem that
f + p = 21 and 4f = 24 + p
rearrange the 2nd equation to get p = 4f - 24 and substitute into the other equation
so...
f + 4f - 24 = 21
5f - 24 = 21
5f = 45
f = 9 - height of the fir tree
substitute back into the 1st equation
9 + p = 21
p = 12 - height of the pine tree
