What is the value of the expression below when r = 4 and t = 6

To train for a bicycle road race, Enrique needs to ride 150 miles per week at an average rate of 25 miles per day. The equation gives the number of miles, M, left to ride after d days. Graph the number M of miles Enrique has left to ride after d days? Tamika’s savings account earned $90.00 in interest. This amount is 1.5% of her total savings. ................
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