Given
-11.2+4(2.1+q) = -0.8
Take -11.2 to the right hand side of the equation (sign will change when we move it to the other side)
∴ 4(2.1+q) = -0.8 + 11.2
Simply both sides
∴ 4*2.1 + 4*q = 11.2-0.8
∴ 8.4 + 4q = 10.4
Take 8.4 to the right hand side
∴ 4q = 10.4 - 8.4
∴ 4q = 2
∴ q = 2/4
∴ q = 1/2 = 0.5
Let the base price be x, cost of tow package be y and cost of hard be z.
So equation for three variables are,
Substract equation x + z = 24890 from equation x + y + z = 25285 to obtain the value of y.
Substract equation x + y = 24290 from x + y + z = 25285 to obtain the value of z.
Substitute the values in the equation x + y +z = 25285 to obtain the value of x.
So base price is $23895, cost of tow package is $395 and cost of hard top is $995.
Is this a school question or your question, if school then is it a multiple choice?
Since we can't use a zero at the start and end, then we have 810 different ways.
If we can't have a leading digit of zero, then we still have 9 available digits to choose from (9P1)
Now, the second term can be of any number, so we will have 10 different digits to choose 1 (10P1)
Now, the final term cannot be a zero, so we will have 9 available digits to choose from (9P1)
Hence, our final number of ways is: 9 × 10 × 9 = 810 ways.