To solve the equation (x−3)(x−4)(x−5)(x−6)=1680, we can follow these steps:
Step 1: Expand the equation
Step 2: Set it to zero and rearrange
Step 3: Solve for x
Let's proceed with these steps:
Step 1: Expand the equation
Expand the left side of the equation (x−3)(x−4)(x−5)(x−6) using the FOIL method (First, Outer, Inner, Last):
(x−3)(x−4)(x−5)(x−6)=(x2−7x+12)(x2−11x+30)
Step 2: Set it to zero and rearrange
Now we have:
(x2−7x+12)(x2−11x+30)=1680
Subtract 1680 from both sides to set the equation to zero:
(x2−7x+12)(x2−11x+30)−1680=0
Step 3: Solve for x
Now, we need to find the solutions for x. We can use various methods, but in this case, we can try to factorize the equation further:
(x2−7x+12)(x2−11x+30)−1680=(x2−7x+12−40)(x2−11x+30)=(x2−7x−28)(x2−11x+30)=0
Now, we have two quadratic equations:
x2−7x−28=0 and x2−11x+30=0
Let's solve them one by one:
For x2−7x−28=0:
To factorize, we look for two numbers that multiply to give -28 and add up to -7. Those numbers are -4 and 7.
So, x2−7x−28=(x−4)(x+7)=0
Setting each factor to zero:
x−4=0⇒x=4
x+7=0⇒x=−7
For x2−11x+30=0:
To factorize, we look for two numbers that multiply to give 30 and add up to -11. Those numbers are -5 and -6.
So, x2−11x+30=(x−5)(x−6)=0
Setting each factor to zero:
x−5=0⇒x=5
x−6=0⇒x=6
Now we have four potential solutions for x: x=4, x=−7, x=5, and x=6.
However, we should check whether any of these solutions make the original equation undefined (e.g., division by zero) or result in the left-hand side being equal to zero.
Let's plug each value back into the original equation (x−3)(x−4)(x−5)(x−6)=1680 and see which ones satisfy the equation:
x=4:
(4−3)(4−4)(4−5)(4−6)=1∗0∗(−1)∗(−2)=0=1680
x=−7:
(−7−3)(−7−4)(−7−5)(−7−6)=(−10)∗(−11)∗(−12)∗(−13)=17160=1680
x=5: