Current location - Training Enrollment Network - Mathematics courses - Seventh grade mathematics 3.4 Volume I
Seventh grade mathematics 3.4 Volume I
9. Set X kilograms of flour to make big moon cakes and (4,500-x) kilograms of flour to make small moon cakes, so as to make the most boxed moon cakes.

According to the meaning, x/0.05/2=4500-x/0.02/4.

Solution: x=2500

4500-x=4500-2500=2000

Answer: It takes 2,500 Jin of flour to make big moon cakes, and 2,000 Jin of moon cakes to make small moon cakes, in order to make the most boxed moon cakes.

10. solution: suppose that only Xiao Qiang has traveled x kilometers and Xiaogang has traveled (x+24) kilometers. The hillock speed is x/2km/h, and the hillock speed is x+24/2 km/h. ..

(x+24/2) ×0.5=x according to the meaning of the question.

The solution is x=8.

So x/2 = 8/2 = 4, x+24/2 = 8+24/2 = 16.

After meeting Xiao Qiang, the time required to get to A is:

x+24/4=8+24/4=8

A: Xiao Qiang travels at a speed of 4 km/h, Xiaogang travels at a speed of 16km/h, and Xiao Qiang reaches a certain place after 8 hours of rendezvous.

1 1. solution: the sales volume is increased by x% compared with the original price.

According to the meaning of the question: (1-20%) (1+x%) =1.

Solution: x=25

A: The sales volume will increase by 25% over the original price.

Hope to adopt!