Question

4x - 9 = 2x + 7​.
I need correct explanation with please.​

Answer 1

8

Explanation:

4x - 9 = 2x + 7

4x - 2x = 7 + 9

2x = 16

x = 16 / 2

x = 8

Answer 2

★ How to do:-

Here, we are given with an equation in which we are given with some constants and two same variables x. We are said that the LHS and RHS are equal to each other. We are asked to find the value of the variable x. To find the value of x, we use an other concept which helps us to find the value of x and also to verify our answer. This concept is called as the transposition method. While using this method, the sign of the appropriate number or variable changes. We use this method to shift the numbers and variables on two separate sides. We can also verify our answer at the end of our answer by verification method. So, let's solve!!

`\:`

➤ Solution :-

`{\sf \leadsto 4x - 9 = 2x + 7}`

Shift the variable value to LHS and the constant value to RHS, changing it's sign.

`{\sf \leadsto 4x - 2x = 7 + 9}`

Subtract the values on LHS and add the values on RHS.

`{\sf \leadsto 2x = 16}`

Shift the number 2 from LHS to RHS.

`{\sf \leadsto x = (16)/(2)}`

Simplify the fraction to find the value of x.

`{\sf \leadsto x = 8}`

`\:`

`{\red{\underline{\boxed{\bf So, \: the \: value \: of \: x \: is \: 8.}}}}`

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Verification :-

`{\sf \leadsto 4x - 9 = 2x + 7}`

Substitute the value of x.

`{\sf \leadsto 4(8) - 9 = 2(8) + 7}`

Multiply the numbers in the bracket.

`{\sf \leadsto 32 - 9 = 16 + 7}`

Subtract the values on LHS and add the values on RHS.

`{\sf \leadsto 23 = 23}`

So,

`{\sf \leadsto LHS = RHS}`