Does anyone know how to do this

Answer: 7(x+2)(x+3)
Step-by-step explanation:
First, you want to find the GCF, 7 goes into all the terms evenly
so 7x^2 + 35x + 42 = 7(x^2 + 5 + 6)
to factor (x^2+5+6), you want to find two numbers whose product is 6 and whose sum is 5 (2 and 3)
so (x^2 + 5 + 6) becomes (x+2)(x+3)
and 7(x^2 + 5 + 6) becomes 7(x+2)(x+3)
Answer is 7(xsquared+5x+6)
Step by step:
all of the coefficients are divisible by seven so divide them y 7 and put 7 outside the parenthesis