Solve the system by substitution 5x+y=-10. 4x-7y=-8

x = -2 and y = 0

Step-by-step explanation:

5x + y = -10

4x - 7y = -8

Rearrange the first equation to equal y.

5x + y = -10

y = -10 - 5x

Replace y in the second equation with the first equation.

4x - 7y = -8

4x - 7(-10 - 5x) = -8

4x - (-70 -35x) = -8

4x + 70 + 35x = -8

Rearrange the equation to find x.

4x + 35x = -8 - 70

39x = -78

x = -2

Now that you know x, use the rearranged first equation to find y.

y = -10 - 5x

y = -10 - 5(-2)

y = -10 + 10

y = 0

1gm = 1000mg so 0.1gm = 1000mg

first, convert the weight to kg

160lb * 1kg/2.2lb = 72.7kg

next, the dose

72.7kg * 100mg/kg = 7270mg

simplifying

5(x + -6) = 2(x + 3)

reorder the terms:

5(-6 + x) = 2(x + 3)

(-6 * 5 + x * 5) = 2(x + 3)

(-30 + 5x) = 2(x + 3)

reorder the terms:

-30 + 5x = 2(3 + x)

-30 + 5x = (3 * 2 + x * 2)

-30 + 5x = (6 + 2x)

solving

-30 + 5x = 6 + 2x

solving for variable 'x'.

move all terms containing x to the left, all other terms to the right.

add '-2x' to each side of the equation.

-30 + 5x + -2x = 6 + 2x + -2x

combine like terms: 5x + -2x = 3x

-30 + 3x = 6 + 2x + -2x

combine like terms: 2x + -2x = 0

-30 + 3x = 6 + 0

-30 + 3x = 6

add '30' to each side of the equation.

-30 + 30 + 3x = 6 + 30

combine like terms: -30 + 30 = 0

0 + 3x = 6 + 30

3x = 6 + 30

combine like terms: 6 + 30 = 36

3x = 36

divide each side by '3'.

x = 12

simplifying

x = 12

this should .