The expression that equals 3C - 3D in standard form is written as 3t² - 18t - 39 = 0.
The standard form of writing quadratic equations.
To determine the standard form of the quadratic equation, we need to follow the following steps. Let us find the difference in the algebraic expressions given.
Given that:
- C = t² - 4t - 7; 3C will be = 3(t² - 4t - 7)
- D = 2t + 6; 3D will be = 3(2t + 6)
3C = 3t² - 12t - 21
3(2t + 6) = 6t + 18
Now, the difference of these algebraic equation is:
= (3t² - 12t - 21) - (6t + 18)
Combine like terms
= 3t² - 12t - 6t - 21 - 18
= 3t² - 18t - 39
Since the standard form of a quadratic equation is represented as: ax² + bx + c = 0. Then the expression that equals 3C - 3D in standard form is written as 3t² - 18t - 39 = 0.