When you reverse the digits in a certain 2 digit number you decrease its value by 81 what is the number if you sum of its digits is 9?

90

Step-by-step explanation:

The multiples of 9, when adding the digits of the multiple together, will always produce the number 9.  In this case, 81, or 8 + 1 = 9.  Since the problem says the sum of the digits is 9, then we are looking for a two-digit multiple of 9.  Using the next multiple, 90, we see that 9 + 0 = 9 and if we reverse the digits to 09, we see that 90 - 9 = 81, which is a decrease in value of 81.

gaddgad

step-by-step explanation:

3.4 pizzas

step-by-step explanation:

given is a scatter plot showing number of pizzas sold during weeks for different issues of coupon

y represents number of pizzas sold and x number of coupons issued

y is marked verticaly and x horizontally

the trend line is given as

y =3.4x+43

this says that even when no coupon is issued pizzas sold will be 43

and rate of change of pizza sold for 1 unit of coupon = slope = 3.4

i.e. when x increases by 1 unit y increases by 3.4 units

hence for each additional coupon issued 3.4 pizzas more will be sold