Answer:
For equation 21-b=11 given in the statement
the answer is b=10
Step-by-step explanation:
This is the equation: 21-b=11
If we sum '-21' to both sides of equation, we have
21-b-21=11-21, which leaves us to: -b=-10
Now lets multiply the equation from above by '-1', we obtain that b=10
Answer:
-4
Step-by-step explanation:
2x + 5 = 85
2x = 80
x = 40
3x/(10-x)
3(40)/(10-40)
120/-30 = -4
Answer:
(9,3)
Step-by-step explanation:
x = 9, y = 3
Answer:
8, 9, 10
Step-by-step explanation:
three positive consecutive integers
x, x + 1, x + 2
the product of the smallest and the largest is 26 more than six times the middle integer
x(x + 2) = 6(x + 1) + 26
Expand
x^2 + 2x = 6x + 6 + 26
Combine like terms
x^2 + 2x = 6x + 32
Subtract 6x + 32 from both sides
x^2 - 4x - 32 = 0
Factor
(Alternately use the quadratic formula or complete the sqaure)
(x - 8)(x + 4)
x = {-4, 8}
-4 is extraneous because the integers must be positive
x = 8
x + 1 = 9
x + 2 = 10
8, 9, 10
I'm not gonna prove the formula, but here's the solution. Notice how the degree cancel each other out.