Question

If 5 + 20 times 2 Superscript 2 minus 3 x Baseline = 10 times 2 Superscript negative 2 x Baseline + 5, what is the value of x? –3 –2 2 3

Answer 1

Answer:

d

Step-by-step explanation:

Just did it.

Answer 2

Answer:

Option D) 3 is correct

Therefore the value of x is 3

Step-by-step explanation:

Given equation is $5+20\times (2)^{2-3x}=10\times (2)^{-2x}+5$

To find the value of x :

First solving the given equation we have,

$5+20\times (2)^{2-3x}=10\times (2)^{-2x}+5$

$5+20\times (2)^{2-3x}-5=10\times (2)^{-2x}+5-5$

$20\times (2)^{2-3x}=10\times (2)^{-2x}$

$20\times (2)^2.(2)^{-3x}=10\times (2)^{-2x}$

$20\times 4.(2)^{-3x}=10\times (2)^{-2x}$

$80(2)^{-3x}=10\times (2)^{-2x}$

$\frac{80}{10}(2)^{-3x}=\frac{10\times (2)^{-2x}}{10}$

$8(2)^{-3x}=(2)^{-2x}$

$\frac{(2)^{-3x}}{(2)^{-2x}}=\frac{1}{8}$

$(2)^{-3x}.(2)^{2x}=\frac{1}{2^3}$ ( by using the property $\frac{1}{a^{-m}}=a^m$ )

$2^{-3x+2x}=\frac{1}{2^3}$ ( by using the property $a^m.a^n=a^{m+n}$ )

$2^{-x}=\frac{1}{2^3}$

$\frac{1}{2^x}=\frac{1}{2^3}$ ( by using the property $a^{-m}=\frac{1}{a^m}$ )

Since bases are same so powers are same

Therefore we can equate the powers we get x=3

Therefore the value of x is 3

Option D) 3 is correct