Answer:
x = -2
, y = 3
Step-by-step explanation:
Solve the following system:
{4 x + 5 y = 7
y = 3 x + 9
Hint: | Perform a substitution.
Substitute y = 3 x + 9 into the first equation:
{4 x + 5 (3 x + 9) = 7
y = 3 x + 9
Hint: | Expand the left hand side of the equation 4 x + 5 (3 x + 9) = 7.
4 x + 5 (3 x + 9) = (15 x + 45) + 4 x = 19 x + 45:
{19 x + 45 = 7
y = 3 x + 9
Hint: | Choose an equation and a variable to solve for.
In the first equation, look to solve for x:
{19 x + 45 = 7
y = 3 x + 9
Hint: | Isolate terms with x to the left hand side.
Subtract 45 from both sides:
{19 x = -38
y = 3 x + 9
Hint: | Solve for x.
Divide both sides by 19:
{x = -2
y = 3 x + 9
Hint: | Perform a back substitution.
Substitute x = -2 into the second equation:
Answer: {x = -2
, y = 3
4 5/8
you see how many time 8 goes into 37 which is 4 and then you have 5 left over
Answer:
5/7 = x
Step-by-step explanation:
(6x – 5) – x=3 =2(x + 1) (distribute them)
6x + 10 - 15x = 3 - 2x + 2
-9x + 10 = 5 - 2x
10 - 5 = -2x + 9x
5 = 7
5/7 = x
Answer: 41.296
Step-by-step explanation:
Simply type 71.2*0.58 into a calculator for the answer. If you want to know how to multiply with decimals, just comment and I'll explain.
Hope it helps <3
Answer:
x = - 13, x = - 3
Step-by-step explanation:
Given
x² + 16x = - 39
To complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(8)x + 64 = - 39 + 64
(x + 8)² = 25 ( take the square root of both sides )
x + 8 = ±
= ± 5 ( subtract 8 from both sides )
x = - 8 ± 5, thus
x = - 8 - 5 = - 13 or x = - 8 + 5 = - 3