The cost of 10 donuts and 2 cakes is the same. If the cost of 3 cakes and 5 donuts is $8, find the cost of a cake.

$2

Step-by-step explanation:

Let the cost of a donut and a cake be $d and $c respectively.

10d= 2c

Dividing both sides by 2:

5d= c (1)

3c +5d= 8 (2)

Substitute (1) into (2):

3c +c= 8

Simplify:

4c= 8

Divide both sides by 4:

c= 8 ÷4

c= 2

∴ The cost of a cake is $2.

the first question mark is 6 and the second question mark is 26 (the square root)

step-by-step explanation:

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)