How to solve this problem by classifying systems of equations
3x+4y=36
-5x=35-3y

x=-32/29

Step-by-step explanation:

3x+4y=36 Equation 1

-5x+3y=35 Equation 2

Multiplying equation 1 with 3 (value before y in equation 2) and equation 2 with 4 (value before y in equation 1) we obtain equations 3 and 4 as follows

9x+12=108 equation 3

-20x+12y=140 equation 4

Subtracting equation 3 from equation 4 we obtain

-29x=32

x=-32/29

To find the value of y, we substitute the value of x into equation 2 as initially given in the equation

-5(-32/29)=35-3y

-5(-32/29)-35=-3y

d. $180

step-by-step explanation:

if the dimensions of the room is 9ft by 12 ft, we have the area of the floor as,

so the area of the floor is 108 square feet, converting that into square yards we get,

the cost of carpet is $15 per square yard, therefore the cost of carpet for 12 square yards is,

hence, the cost of carpet is $180.

assuming the dimensions of the room be,

15 ft by 12 ft

so, the area of the floor of that room is,

we can convert 180 square feet into square yards, we know that,

1 sq ft = 0.111 sq yard

so, 180 square feet is,

so the area of floor is 20 square yards.

now, the cost of carpet is 15 dollars per square yard, therefore the cost of carpet for 20 square yards is,

so, it will cost $300.

see explanation

step-by-step explanation:

a

(6r + 7) + (13 + 7r) ( remove brackets and collect like terms )

= 6r + 7 + 13 + 7r

= 13r + 20

b

remove brackets and collect like terms

13 - r - 1 + r

= 12 - r

c

remove brackets and collect like terms

= - 8 - r + 2r - 4

= - 12 + r

d

remove brackets and collect like terms

= 7r - - - 6r

[-   - = - - = - ]

= r -