1st let's calculate r the common ratio:
r = (-20)/4 = (100/-20) = -5
Value of nth term = a₁.rⁿ⁻¹, where a₁= 1st term and n, the rank
Value of nth term = 4r⁽⁷⁻¹⁾ = 4.(-5)⁶
Value of nth term = 62,500
Formula: XM= x1+x2/2 YM: y1+y2/2
end point: (14,-7)
First divide both sides by 2 so that we can get rid of the parentheses, so we get

now subtract 5 from both sides

then finally we want x alone so we'll divide both sides by 3 and get our final answer!