To solve the equation, a quarter of X + 25 percent of x equals five sixths

To solve the equation, a quarter of X + 25 percent of x equals five sixths

¼ X + 25% x = 5 / 6, so there are 189; X = 5 / 6, so x = 5 / 3

Solving equation exercise: x + X / 9 = 0. X =?

x+x/9=0
10/9 x=0
x=0

How much is minus four and six times eight and three fifths?

One thousand two hundred forty-seven out of thirty

How to divide 640 by 16?

640 divided by 16 = 40 × 16 △ 16 = 40

A simple algorithm of (60-144 divided by 12) divided by 16

（60-144/12）/16=
（60-12）/16=
48/16=
three

There are seven numbers 79, 80, 79.2, 78, 78.3, 79.5 and 80.4. Can you calculate their average quickly? Please tell me your simple calculation method

Subtract 80 from all, and then add 80, that is - 1,0, - 0.8, - 2, - 1.7, - 0.5, 0.4, and the average is - 0.8, so the average is 80-0.8 = 79.2

77 / 78 × 79 process

（77*79）/78
=（78-1）（78+1）/78
=78²-1/78
=78-1/78
≈77.987
complete!

Simple algorithm of 35 * 68 + 68 + 68 * 35

Common factor 68
68（35+1+35）
=68×71
=（70-2）×（70+1）
=70×70-140+70-2
=4900-70-2
=4828

How to calculate 35 × 68 + 68 + 68 × 64 and 800 △ 25 with simple algorithm?

35×68+68+68×64
=(35+1+64)×68
=100×68
=6800
800÷25
=(800×4)÷(25×4)
=3200÷100
=32

A simple and convenient method of 69 △ (69 + 69 / 70)

69÷(69+69/70)
=69÷[69×(1+1/7)]
=69÷(69×8/7)
=69÷69÷8/7
=1÷8/7
=1×7/8
=7/8