The staircase has treads that are 10 inches deep with 7 inch high risers. If the staircase needs to reach a total height of 8 feet, 2 inches. How much floor space needs to be allowed for the staircase?

140 inches

Step-by-step explanation:

The design of the staircase treads is 10 inches deep and 7 inches rise.

The total height of the staircase is 8 feet and 2 inches.

Present the height of staircase in inches as;

1 foot = 12 inches

8 ft=?

Apply cross-product as (8*12)/1 =96 inches

Total height in inches of the staircase= 96+2 = 98 inches

Finding the number of times the tread's height fits in the total height will be;

98/7 =14 times

The floor space for the staircase will thus be; 10*14 =140 inches

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

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