Question

1)x+x/4=15/8 2)(3/5-3/4):3/40 3) (6a-6)(6a+6)-6a(6a+6) при а=5,5

Answer 1

1)

(4х+х)/4=15/8

5х/4=15/8

Про порцией

5х×8=4×15

40х=60

Х= 60/40

Х=6/4 = 3/2 = 1,5

2)

(3×4-3×5)/20 : 3/40 = -3/20 : 3/40 = -(3/20 × 40/3) = -1/20 × 40/1 = -2

3)

36а²-36-36а²-36а= -36(1+а)= -36×6,5 = -234

Answer 2

Let's solve each of the given equations step-by-step:

1. x + x/4 = 15/8

To solve this equation, we need to isolate the variable x on one side of the equation. First, we'll combine the terms with x:

x + x/4 = 15/8

To add x and x/4, we need a common denominator, which is 4. So, the equation becomes:

(4x + x) / 4 = 15/8

Now, simplify the left-hand side of the equation:

5x / 4 = 15/8

To isolate x, we can multiply both sides of the equation by 4/5:

(4/5) * (5x / 4) = (4/5) * (15/8)

x = 3/2

So, the value of x is 3/2.

2. (3/5 - 3/4) / (3/40)

To solve this expression, first, find a common denominator for the fractions:

Common denominator for (3/5) and (3/4) is 20.

Now, rewrite the expression:

[(12/20) - (15/20)] / (3/40)

Combine the fractions:

(-3/20) / (3/40)

To divide by a fraction, multiply by its reciprocal:

(-3/20) * (40/3)

Now, simplify the expression:

-2/1

The result is -2.

3. (6a-6)(6a+6) - 6a(6a+6) when a = 5.5

Replace 'a' with 5.5 in the expression:

(6 * 5.5 - 6)(6 * 5.5 + 6) - 6 * 5.5(6 * 5.5 + 6)

Now, calculate the expression:

(33 - 6)(33 + 6) - 6 * 33(33 + 6)

(27)(39) - 6 * 33(39)

1053 - 6 * 33 * 39

1053 - 765

The result is 288.