7. A shirt marked at $600 is sold at 30% off. (a) Find the selling price of the shirt.
(b) If the shirt is sold at a profit of 5%, find the cost pric

a) $420 b) $399

Step-by-step explanation:

a) $600 = 100%

$60 = 10%

$60 times 3 gives 30% = $180

$600 - $180 = $420

b) $420 = 100%

$42 = 10%

$21 = 5%

this means, they profitted by $21.

so $420 - $21 = $399

therefore, $399 is the cost price

10a^3+277a^2-132a-792

step-by-step explanation:

(2a+11)(5a-12)(foil)

=10a^2-24a+55a-132 =10a^2+31a-132

(10a^2+31a-132)(a+6)

=10a^3+60a^2+31a^2+186a^2-132a-792 =10a^3+277a^2-132a-792

i hope this is what you are looking for : )