a textbook store sold a combined total of 367...

a textbook store sold a combined total of 367 sociology and psychology textbooks in a week. the number of psychology textbooks sold was 55 less than the number of sociology textbooks sold. how many textbooks of each type were sold?\nnumber of sociology textbooks sold:\nnumber of psychology textbooks sold:

Answer

# Explanation: ## Step1: Let variables Let $x$ be the number of sociology textbooks sold and $y$ be the number of psychology textbooks sold. We know that $x + y=367$ and $y=x - 55$. ## Step2: Substitute $y$ into the first - equation Substitute $y=x - 55$ into $x + y=367$, we get $x+(x - 55)=367$. ## Step3: Simplify the equation Expand the left - hand side: $x+x - 55=367$, which simplifies to $2x-55 = 367$. ## Step4: Solve for $x$ Add 55 to both sides of the equation: $2x=367 + 55=422$. Then divide both sides by 2: $x=\frac{422}{2}=211$. ## Step5: Solve for $y$ Substitute $x = 211$ into $y=x - 55$, we get $y=211-55 = 156$. # Answer: Number of sociology textbooks sold: 211 Number of psychology textbooks sold: 156