Mmmmbrntnrjneuneunre unenriched
By synthetic division, the quotient (4x^2 -10x -24)/(2x +3) is 2x -8.
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You have not actually said what division you want performed.
R-7=7 add the seven from both sides, leaving the r alone, because this is what you are trying to find. Thus the answer is r=14.