2.6 because you substract
x will represent the first unknow number
6x will represent the second number
the two numbers together will equal 21
6x + x = 21 combine like terms
7x =21 divide both sides by 7
x =3
Hope that helps.
brainliest is always appreciated.
Answer:
12a^3+30a^2
Step-by-step explanation:
6a^2(2a+5)
12a^3+30a^2