Question

Which situation illustrates quadratic equation?

Answer 1

Complete Question:

Which situation illustrates quadratic equation?

a. The length of a rectangular board is 3m longer than its width and its perimeter is 25m.

b. Joey paid at least P2,000 for the shirt and pants.The cost of pants is P700 more than the shirt.

c. A garden's length is 7m longer than its width and the area is 18 square meter.

d. A lot costbP4,000 per square meter and the area is 120 square meters.

Answer:

C.

Step-by-step explanation:

Required

Determine which option answers the question, correctly.

From the list of given options, only option c answers the question correctly.

This is shown below.

Represent

Length with l and Width with w, such that:

$l = 7 + w$

Area (A) is calculated as thus:

$A = l * w$

Substitute 7 + w for l and 18 for A.

This gives:

$18 = (7 + w) * w$

Open Bracket

$18 = 7w + w^2$

Reorder

$w^2 + 7w = 18$

Subtract 18 from both sides

$w^2 + 7w - 18= 18 - 18$

$w^2 + 7w - 18= 0$

See that the above expression is a quadratic equation.