Current location - Plastic Surgery and Aesthetics Network - Clothing company - Application of linear equation with one variable
Application of linear equation with one variable
1. Let the first number be x, then x+4 should be equal to the second number minus 4, so the second number is (x+8).

Similarly, the third number is (x+4)/4, and the fourth number is 4*(x+4).

x+(x+8)+(x+4)/4+4 *(x+4)= 100

The solution is x= 12.

The first number is 12, the second number is 20, the third number is 4 and the fourth number is 64.

2. Set the purchase price to X yuan.

( 1)x+x*50%= 180,x= 120。

(2)x+x* 100%= 180 gives x=90.

So the purchase price of this dress should be between 120 yuan -90 yuan.

If you make a counter-offer at 20% of the purchase price, it will be 90+90*20%= 135,120+120 * 20% =144.

So the counter-offer should be between 135 yuan and 144 yuan.

3.( 1)a * 0.40+(84-a)* 0.40 * 70% = 30.72

The solution is a=60.

(2) Let the electricity consumption in June be X degrees.

0.36*x=0.40*60+(x-60)*0.40*70%

The solution is x= 105.

105*0.36=37.8

So he used 105 kwh of electricity in June and paid 37.8 yuan for electricity.