Question

Решить уравнени показав действи 1. 0,25х +0,4х=7-0,35 2. 4(2,5-х)-4,5=12,5 3. 0,3х-0,8х+5=х-4 4. 2,5х+9,5=3-х

Answer 1

1. 0,25х +0,4х=7-0,35; 0,65х=6,65; Х=6,65:0,65; х=665/100*100/65; Х=665/65=10 3/13;/// 2. 4(2,5-х)-4,5=12,5; 4(2,5-х)=12,5+4,5; 2,5-х=17/4; -х=4 1/4-2 1/2; -Х=17/4-10/4; Х=-7/4; х=-1 3/4;///// 3. 0,3х-0,8х+5=х-4; -0,5х-х=-4-5; -1,5х=-9; Х=-9:-1,5; Х=6;//// 4. 2,5х+9,5=3-х; 2,5х+х=3-9,5; 3,5х=-6,5; Х=-6,5:3,5; Х=-65/35; Х=-1 6/7

Answer 2

1. 0.25x + 0.4x = 7 - 0.35

Combining like terms on the left side:

0.65x = 6.65

Divide both sides by 0.65:

x = 10.23

Therefore, the solution to the equation is x = 10.23.

2. 4(2.5 - x) - 4.5 = 12.5

Distribute the 4 on the left side:

10 - 4x - 4.5 = 12.5

Combine like terms:

-4x + 5.5 = 12.5

Subtract 5.5 from both sides:

-4x = 7

Divide both sides by -4:

x = -7/4

So the solution to the equation is x = -7/4 or -1.75.

3. 0.3x - 0.8x + 5 = x - 4

Combine like terms on the left side:

-0.5x + 5 = x - 4

Add 0.5x to both sides:

5 = 1.5x - 4

Add 4 to both sides:

9 = 1.5x

Divide both sides by 1.5:

x = 6

Hence, the solution to the equation is x = 6.

4. 2.5x + 9.5 = 3 - x

Add x to both sides:

2.5x + x + 9.5 = 3

Combine like terms:

3.5x + 9.5 = 3

Subtract 9.5 from both sides:

3.5x = -6.5

Divide both sides by 3.5:

x = -6.5/3.5

Simplifying the result:

x = -1.857

Therefore, the solution to the equation is x = -1.857.