Answer:
X=-4, y=-7
Step-by-step explanation:
6x-5y=11. 1st equation
y=7x+21 2nd equation
6x-5(7x+21)=11. Sub value of y in 2nd equation (7x+22) into 1st equation
6x-35x-105=11. Solve by distributative property
-29x-105=11. Add x values
-29x=116. add 105 to both sides
x=-4. Solve for x
solve for y:
y=7x+21
y=7(-4)+21
y=-28+21
y=-7
check answer by substituting x and y into either equation
6x-5y=11
6(-4)-5(-7)=11
-24+35=11
11=11
It takes 6 minutes to circulate 2.5 gallons of water
X = smaller number, y = larger number
x + y = 15.....x = 15 - y
4x = 2y - 60
4(15 - y) = 2y - 60
60 - 4y = 2y - 60
60 + 60 = 2y + 4y
120 = 6y
120/6 = y
20 = y <==== larger number is 20
x + y = 15
x + 20 = 15
x = 15 - 20
x = - 5
