Combine like terms

a + 7b + 3a - 4b + 5c

4a + 3b + 5cSweetheart to get the answer simply get the two coefficients.(Coefficients: Numbers that have a variable next to them)(Variables: A symbol for a value we don't know yet ; Ex. x, y, a etc.)Then add them together, but since there are multiple variables you add the separately.a + 3a = 4a (The 'a' alone makes the 'a' become a one) Then subtract the variables that need to be subtracted.7b - 4b = 3bThen since '5c' is the only variable with 'c' you leave it alone as it it.Finally you mix all variables back together to get.4a + 3b + 5c

Hope you have a good day, Loves!~

A= r2 × 3.14 7x7 ↓ ↓ 49 × 3.14 = 153.86 → 153.9