3a to the second power minus 2 a=5
Don't forget completing the square, which is often easier and faster than the quadratic formula.
Sorry. Somehow this was posted to the wrong question.
3a to the second power minus 2 a=5
Don't forget completing the square, which is often easier and faster than the quadratic formula.
Sorry. Somehow this was posted to the wrong question.
3a^{2 }- 2a = 5
1. Subtract 5 from both sides, so we have ZERO on the right side:
3a^{2} - 2a - 5 = 0
2. Factor:
(3a - 5) (a + 1) = 0
Now we know that at least one of the values in the parentheses has to equal ZERO, because anything multiplied by Zero is going to equal Zero.
3. Solve each parentheses separately:
3a - 5 = 0 --> 3a = 5 --> a = 5/3
a + 1 = 0 --> a = -1
Answer: a = 5/3 or -1
**Remember you can always double check your answer by plugging it into the original equation!
Comments
Assuming 3a to the second power means only the a is raised to the second power.
3a^2 - 2a = 5
3a^2 - 2a - 5 = 0
(a+1) * (3a-5) = 0
a= -1 or a= 5/3
Plug in both answers to verify they work and they do.
it is 3 a^2-2 a=5
Cierra, if you know that a=5 then you can plug 5 into the equation for "a" and solve it using the order of operations:
3 * (5)^{2} - 2 --> 3 * 25 -2 --> 75 - 2 = 73
Order of Operations:
Parentheses, Exponents, Multiplication, Division, Addition, Subtraction