What digit out of 1, 3,5, and 9 would complete the second factor so that the product will have 2 decimal places for 7.2 x 4.

When we have multiple possibilities for a number, we can replace it with a letter (or variable) -- here, we can put the second decimal place for 4.6_ as y. Therefore, when we multiply the two numbers, 7.2*4.6y=

        7.2

    x  4.6y

        7.2*y

       4.320

     28.800  

Therefore, if we add 28.8 and 4.32 up, we are at 33.12. Aligning the zeros, it is clear that if the last digit of 7.2*y is not 0, this equation will end up having more than 2 decimal places. Therefore, using a little guess and check, we have 7.2*1=7.2, 7.2*3=21.6, 7.2*5=36.0, and 7.2*9=648. Therefore, 5 is our answer.

Feel free to ask further questions, and Happy Holidays!

c. y = 1/4 x + 5

step-by-step explanation:

first, put the equation of the line on the graph into slope-intercept form

(y = mx + b):   y = -4x + 8

second, a perpendicular line has to have "an opposite/reciprocal slope" to the original slope. so, find the "m" value in your original equation (it's -4, right? )

original slope: m = -4   perpendicular slope: change the sign to its opposite and find the reciprocal ("flip" the number)

new slope is now positive (b/c the original slope was negative 4), and it's 1/4 (not the original slope of 4 or 4/1)