Factor

c^2+3c-54

v^2-4v-21

(c+9)(c-6)

and
(v-7(v+_)

Fill in the blank

54 = 6*9 differ by three, what we need

(c+9)(c-6)
Oh, see wls has it :)

(v+3)

To factor the quadratic expressions, let's look at each one separately:

For the expression c^2 + 3c - 54:

Step 1: In this case, you want to find two numbers that multiply to -54 and add up to +3 (because the coefficient of c is positive). The numbers that satisfy these conditions are +9 and -6.

Step 2: Rewrite the quadratic expression by splitting the middle term using these two numbers:
c^2 + 9c - 6c - 54

Step 3: Factor by grouping. Group the first two terms together and the last two terms together, then factor each group separately:
c(c + 9) - 6(c + 9)

Step 4: Notice that you now have a common binomial factor of (c + 9). Factor it out:
(c + 9)(c - 6)

Therefore, the factored form of c^2 + 3c - 54 is (c + 9)(c - 6).

Now let's factor the expression v^2 - 4v - 21:

Step 1: Similar to the previous example, you want to find two numbers that multiply to -21 and add up to -4 (because the coefficient of v is negative). The numbers that satisfy these conditions are -7 and +3.

Step 2: Rewrite the quadratic expression by splitting the middle term using these two numbers:
v^2 - 7v + 3v - 21

Step 3: Factor by grouping. Group the first two terms together and the last two terms together, then factor each group separately:
v(v - 7) + 3(v - 7)

Step 4: Notice that you now have a common binomial factor of (v - 7). Factor it out:
(v - 7)(v + 3)

Therefore, the factored form of v^2 - 4v - 21 is (v - 7)(v + 3).