change the second mixed fraction into an improper one
=> -25/4 ÷ -25/4; dividing a number by itself gives you '1'
=> 1
second question,
=> -3/21 × -3; multiply the numerator with the other numerator, and since there is nothing given in the denominator of the second number mean its 1, hence multiply the denominator with the other denominator, and we get:
