Multiple choice A B C or D?

The radius of the circle is 4 cm and the measure of the central angle is 90° the area of the sector with a central angle measuring 90° and radius of length 4 cm is vt cm the triangle in the sector is 4 cm the area of the triangle is v/cm² the area of the segment of the circle is (471 - ) cm?

What are “like terms”? why can we only add like terms?

Which expression is equivalent to 8(k + m) − 15(2k + 5m)?