Answer: Like terms are -7 and 2. Simplified version would be 7d-5.
Step-by-step explanation:
first you would distribute, so it would be 7(d-1)+2 = 7d-7+2. Combine like terms. The only like terms here are -7 and 2, so just basically subtract -7 from 2 and you would get -5. you can't do anything with 7d because there is no like term for it.
The quadratic formula is above.
You want each equation in standard form: ax^2 + bx + c = 0
I begin each problem by defining variables.
For instance 3. Is in standard form. X^2 -2x - 3 = 0. a = 1, b = -2, c = -3
Now use quadratic formula: x = [- b + or - sqrt(b^2 - 4ac)]\2a
4.07 * 100 = 407%
407 / 100 = 4.07