Mathematics 10 — Exercise Review · Q2 (i)

Full question

For the following functions, find f+g.

f(x)=25-x2g(x)=x+5

Step-by-step solution

  1. Substitute the function expressions, keeping the brackets.

    −(x2-25)+x+5
  2. Remove the brackets. A preceding minus sign reverses every sign inside that bracket.

    −(x2-25)+x+5
  3. Write EVERY distributed product before collecting terms.

    25−x2+5+x
  4. Calculate this individual product, including its sign and powers.

    25=25
  5. Calculate this individual product, including its sign and powers.

    -x2=-x2
  6. Calculate this individual product, including its sign and powers.

    5=5
  7. Calculate this individual product, including its sign and powers.

    x=x
  8. These terms have the same variable part. Add ONLY their coefficients.

    25+5=30
  9. These terms have the same variable part. Add ONLY their coefficients.

    -1=-1
  10. These terms have the same variable part. Add ONLY their coefficients.

    1=1
  11. Put the simplified groups together.

    30−x2+x
  12. Collect terms with the same power and simplify their coefficients.

    -x2+x+30

Answer

The final answer is shown below.

-x2+x+30