Margot spent \( \$ 400 \) this month on propane to heat her home. Her propane company charges \( \$ 3 \) per gallon and she received a \( \$ 20 \) discount for paying in cash. To determine how many gallons of propane she bought, solve for \( x \) in the following equation: \( 400=3 x-20 \) a.) 126.67 gallons b.) 1,260 gallons c.) 140 gallons d.) 266 gallons

5. Tenlikləri hall edin: a) \( a(a-8)+5(a-8)=0 \);

177. Mukul has \( \$ 3.75 \) in quarters, dimes and nickels in his pocket. He has five more dimes than quarters and nine more nickels than quarters. How many of each coin are in his pocket?

Simplify \( \frac{2^{x}-2^{x-1}}{2^{3}-2^{x}-8 \times 2^{x-1}} \)

4. Coxhadlini vuruqlara ayırın: \( \begin{array}{ll}\text { a) } a^{3}-a^{2}+a-1 ; & \text { b) } x^{2}-x z-5 x+5 z \text {; } \\ \text { c) } b^{2}-8 b+12 ; & \text { d) } a(5-b)+8(b-5)\end{array} \)

ii) \( (3-b)\left(9+3 b+b^{2}\right) \)