Linear Algerbra Equation help Thanks

[GladToLearn]

Linear Algerbra Equation help :) Thanks

Homework Statement

Problem 20. Solve for x :
1.25x − 6 = x

1.25x −x = 6

(1.25 − 1)x = 6 On combining the like terms
on the left.
.25 x = 6

x = 24. On multiplying both sides
by 4.

Homework Equations

The Attempt at a Solution

Well i know x = 24. but how does 1.25 0- 1 = .25? how do i get 24x? why do i multiply both sides and why did i multiply them by 4?

My attempt
Problem 20. Solve for x :
1.25x − 6 = x

(1.25-x)
(1.25-1(x) = 6
1.24x = 6
(1.24 = 6 is 1.24 x 6 so i divide right?)
20.0x(rounded the nearest 10th..i think)

20.0x = x
x = 20.0x

 

[mege]

1.25x - 1x = ? (it's not 1.24)

 

[flyingpig]

This is not Linear Algebra or Physics...

I don't understand how you got 1.24 from 1.25 - 1 = 0.25??

 

[Moston-Duggan]

put 1.25 - 1 into your calculator and you will see that 1.25 - 1 = .25

 

[SteamKing]

The OP's problem is he didn't learn how to add and subtract decimals properly in grade school. The OP is ignoring the decimal in 1.25 and is making the subtraction as if it were a multiplication instead, where you do the multiplication on the numbers first and then insert the decimal afterwards.

The OP says: 1.25 - 1 is the same as 125 - 1 = 124 and then places the decimal as original: 124 becomes 1.24 just like
1.25 * 2 is the same as 125 * 2 = 250, put in the decimal and 1.25 * 2 = 2.50