Henrique began to solve a system of linear equations using the linear combination method. his work is shown below: 3(4x – 7y = 28) → 12x – 21y = 84 –2(6x – 5y = 31) → –12x + 10y = –62 12x – 21y = 84 + –12x + 10y = –62 –11y = 22 y = –2 complete the steps used to solve a system of linear equations by substituting the value of y into one of the original equations to find the value of x. what is the solution to the system?

henrique began to solve a system of linear equations using the linear combination method:

given the system of equation :

multiply equation [1] by 3 to both sides we have;

⇒                  

multiply equation [2] by -2 to both sides we have;

⇒              

add equation [3] and [4] to eliminate x and solve for y:

divide both sides by -11 we have;

y = -2

substituting the   value of y into equation [1] to solve for x.

⇒

subtract 14 from both sides we have;

divide both sides by 4 we have;

x = 3.5

therefore, the solution to the system is, (3.5, -2)

step-by-step explanation:

12: 00 p.m. to 7: 00 p.m. is a total of 7 hours.

4: 00 p.m. to 7: 00 p.m. is a total of 3 hours.

this means that from 4: 00 p.m to 7: 00 p.m. this represents 3/7 of what was lost from 12: 00 p.m. to 7: 00 p.m.

after knowing this, after doing 11,600 - 6,800 = 4,800

4,800 represents 3/7 of what was lost for 7 hours.

we then divide 4,800 by 3 which gets 1,600.

because we know that 1,600 represents 1/7 of how much water was lost, we just have to multiply by 7, which gets 11,200.   after adding 11,200 to how much water was left at 7: 00 p.m. which was 6,800. 11,200 + 6,800 = 18,000

this means that the pool originally had 18,000 gallons in the pool.

you can also check your work by doing 18,000 - 4(1600), which becomes           1800 - 6400 which gets you 11,600.

nada

step-by-step explanation: