1-0.8 0.7 + 3x = 0.4 0.3x-1-x

1-0.8 0.7 + 3x = 0.4 0.3x-1-x

x = - 9/26

How to do 3x (7 / 8 + 1 / 6) × 3 / 4

3x of 8 (7 of 8 + 1 of 6) × 3 of 4
=3 / 8 x 24 / 25 x 3 / 4
=75 out of 256

Given that the real number x, y satisfies 3 ^ x = 6,2 * 3 ^ y = 3, then x + y=

It is known that x = logarithm of base 6 with 3, y = logarithm of base 2 / 3 with 3, then x + y = logarithm of base 6 with 3 + logarithm of base 2 / 3 with 3 = logarithm of base 3 multiplied by logarithm of base 2 / 3 (from logarithm formula) = logarithm of base 9 with 3 = 2

If real numbers x, y satisfy x + y = 3, x ^ 2 + y ^ 2 = 7, find the value of x ^ 5 + y ^ 5

If x ^ 2 + y ^ 2 = (x + y) ^ 2-2xy is 7 = 3 ^ 2-2xy, then 2XY = 9-7 = 2XY = 1 x ^ 3 + y ^ 3 = (x + y) (x ^ 2-xy + y ^ 2) = 3 × (7-1) = 18 (x ^ 2 + y ^ 2) (x ^ 3 + y ^ 3) = x ^ 5 + x ^ 2Y ^ 3 + y ^ 2x ^ 3 + y ^ 5, substituting xy = 1 into the above formula, we get x ^ 5 + y ^ 5 + y + x = x ^ 5 + y ^ 5 + 3 and (x ^ 2 + y ^ 2) (x ^ 3 + y ^ 3) = 7 × 18 = 126, that is x ^ 5 + y ^ 5 + 3

To solve the system of equations x + y + Z = √ (x + y + Z + 1) + 5 3 / 2 = Y / 3 = Z / 4 in the range of real numbers

3/2=y/3 2y=9 y=9/2
Similarly, z = 6
21 / 2 + Z = under root (23 / 2 + Z) + 5
1 / 2 + Z = under root (23 / 2 + Z)
Two sides square
1/4+z^2=23/2
z^2-45/4=0
z^2=45/4
Z = positive and negative (3 root sign 5) / 2

Given that X and y are positive real numbers, satisfying 1 ≤ ln (XY) ≤ 2,3 ≤ LNX / Y ≤ 4, there are two answers to the problem of Ln (x ^ 4Y ^ 2) [5,11] and [6,10]
Why is it wrong? Where is it wrong?

First calculate the value range of XY, and then calculate the value range of X / y, so as to get the value range of x ^ 4Y ^ 2, the problem is solved!

If x and y are real numbers and y = x − 3 + 3 − x + 8, find the value of X + y

The solution is x ≥ 3 and X ≤ 3, so x = 3, y = 8, x + y = 3 + 8 = 11

1 / 3 (X-5) = 4 / 9

1/3(X-5)=4/9
(x-5)=4/9X3
(x-5)=4/3
X = 4 / 3 + 5 = 19 / 3 = 6 and a third

How to do 4 ^ (2 / 5 × 1 / 4)

It's 20

How to do it

1. One fifth of 1 + √ 2 + √ 5 = (√ 5 - √ 2) / (√ 5 - √ 2) (√ 5 + √ 2) = (√ 5 - √ 2) / 3 2, 4 / 5 of 1 + √ 2 + √ 5 = [(√ 5 + 1) ^ 2 - (√ 2) ^ 2] / (1 + √ 2 + √ 5) = [(√ 5 + 1 + √ 2) (√ 5 + 1 - √ 2)] / (1 + √ 2 + √ 5) = √ 5 + 1 - √ 2 3