Question

Докажите,что,если: 1)х+8у<4х+5у, то х>у 2)1.2s+5.1t>2s+4.3t, то s

Answer 1

1) х+8у<4х+5у, то х>у
х+8у<4х+5у 
x-4x<5y-8y
-3x<-3y
x>y
2) 1.2s+5.1t>2s+4.3t
1.2s-2s>4.3t-5.1t
-0.8s>-0.8t
s<t

Answer 2

I can help you with your math problem. Here is the detailed solution:

1) х+8у<4х+5у, то х>у

We can simplify this inequality by subtracting х from both sides and rearranging the terms:

8у-5у<4х-х-3у<3х у<х

We can divide both sides by -3, but we have to reverse the inequality sign:

-у>-х у<х

This proves that if х+8у<4х+5у, then у<х.

2) 1.2s+5.1t>2s+4.3t, то s

We can simplify this inequality by subtracting 2s from both sides and rearranging the terms:

-0.8s+5.1t>4.3t -0.8s>-0.8t

We can divide both sides by -0.8, but we have to reverse the inequality sign:

s

This proves that if 1.2s+5.1t>2s+4.3t, then s

I hope this helps. If you need more assistance, you can use this online tool to solve algebra problems step by step. Have a nice day!