p=0.099999... Calculation: Let p=0.09=x. Multiply both sides by 10 : 10x=0.9999 100x=9.99999... 100x−10x=9.99999...−0.99999... 90x=9 x=0.1 So, x=1. Therefore, p=1. p=0.1 into the expression 70p2+43p−5 : 70p2+43p−5=70(0.1)2+43(0.1)−5 =0.70+4.3−5 =0