Question

3x -1 upon 3 +4x =8

solve it​

Answer 1

Answer:

• 3x-1/3+4x=8
• 3x-1=8-3+4x
• 8-3=5
• 3x-1=5+4x now remove '='
• 3x-1-5-4x
• 5+1= -6,+3x-4x= -1x
• -1x-6

is your answer friend

Mark as BRAINLIST friend

Answer 2

Aim : To find x

Question :

$\frac{3x - 1}{3 + 4x} = 8$

By Cross multiplying,

3x - 1 = 8(3+4x)

3x - 1 = 24 + 32x

3x - 32x = 24 + 1

-29x = 25

$x = \frac{25}{ - 29}$

$x = \frac{ - 25}{29}$

Verification:

substituting,

$\frac{(3 \times \frac{ - 25}{29}) - 1 }{3 + (4 \times \frac{ - 25}{29})} = 8$

$\frac{( \frac{ - 75}{29}) - 1 }{3 + ( \frac{ - 100}{29}) } = 8$

$\frac{ \frac{ - 75 - 29}{29} }{ \frac{87 - 100}{29} } = 8$

$\frac{ \frac{ - 104}{29} }{ \frac{ - 13}{29} } = 8$

$\frac{ - 104}{29} \div \frac{ - 13}{29} = 8$

$\frac{ - 104}{29} \times \frac{29}{ - 13} = 8$

$\frac{ - 104} { - 13} = 8$

$\frac{104}{13} = 8$

LHS = RHS.

Hence verified.

Why should we cross multiply?

Let us take an example to understand :

$\frac{8}{2} = 4$

We know that,

2 × 4 = 8

$2 = \frac{8}{4}$

$4 = \frac{8}{2}$

Notice the relation. This is the reason we cross multiply to find out the solutions.