Question

If the cost of a toy car is given to be Rs (3y²-5y + 4) and number of toy cars bought is (2y²+y + 7)

a) Find the total cost in terms of y

. b) Find the value when y-3.​

Answer 1

Step-by-step explanation:

cost of a car = 3y²-5y + 4

number of cars = 2y²+y + 7

a) total cost of the cars

$\\ =(3y^2-5y+4)(2y^2+y+7)\\= 6y^4+3y^3+21y^2-10y^3-5y^2-35y+8y^2+4y+28\\=6y^4-7y^3+24y^2-32y+28$

b) when y=3

$6y^4-7y^3+24y^2-32y+28$

$=6(3)^4-7(3)^3+24(3)^2-32(3)+28\\=6(81)-7(27)+24(9)-96+28\\=486-189+216-68\\=445$