Application of Binary Linear Equations in Math Problems of Junior Two.

1. Five of them are broken. Because of the broken freight, (250×20-4400)/ 120=5.

2. There are X boys,

Then there are 50-X girls 3x+2x50-x = 120-5.

X= 15

50- 15=35

Boys 15. 35 girls

3.( 1) Formula: Assuming that Liu Dongquan is right, you can get 8×20= 160 points.

Deduct 8+4= 12 points for each wrong question (8 points for doing it right and 4 points for doing it wrong).

Wrong: (160-112) ÷12 = 4 questions.

Right: 20-4= 16.

(2) Column equation: if X is right, it will be 20-x wrong.

8x-4(20-x)= 1 12

Get x= 16.

4. Big ship: (52- 1 1× 4) ÷ (6-4) = 4 (pieces)

Ship: 1 1-4 = 7 (pieces)

Suppose a thief stole a wheel from every car. He came twice.

* * * stealing 32×2=64.

The remaining 108-64 = 44. At this time, the motorcycle has no wheels.

Wheels are cars, two for each car.

44 wheels, 22 cars.

The thief found his conscience and returned the wheel. Motorcycle has 32-22= 10.

Brother, I hope I can help you.