Question

If x-y=4 and 2x+3y=10 what is the value of 3x+2y

Answer 1

x-y=4       2x+3y=10     find: 3x+2y

FIrst you need to figure out what either x or y equals with one of the equations. It doesn't matter which, because they are dependent on eachother and will both give the same number at the end.

I chose to go with the first equation, because it was simplier, which makes it easier to find the first variable. Again you can solve for either x or y first, I chose x

x-y=4

becomes

x=4+y

now we can plug this x value into the second equation of 2x+3y=10 to find

2(4+y)+3y=10

8+2y+3y=10

8+5y=10

solving for y

5y=2

y=2/5

Now we can plug this y value into the first equation to get an actual value of x

x-(2/5)=4

x=4+2/5

x=22/5

since we now have both x and y values, x=22/5 y=2/5, we can plug them into the 3rd equation to find what it equals

3(x)+2(y)=??

3(22/5)+2(2/5)=??

66/5+4/5=??

70/5=14

Answer 2

Value of 3x + 2y is 14

Step-by-step explanation:

• Step 1: Given 2 equations are x - y = 4 and 2x + 3y = 10. Multiply the first equation by 2 to make the coefficients equal.

2x - 2y = 8

2x + 3y = 10

• Step 2: Subtract the second equation from the first equation.

⇒ - 5y = -2

∴ y = 2/5

⇒ x - 2/5 = 4

∴ x = 4 + 2/5 = 22/5

• Step 3: Find the value of 3x + 2y

⇒ 3x + 2y = 3 × 22/5 + 2 × 2/5 = 66 + 4/5 = 70/5 = 14