Page 56 - 新思维数学学生用书8 样章

2.6 Inequalities

14 Art has these cards.

2y + 14 8(y − 12) y − 18 = 4 −2 −20
4

He chooses one blue card, the red card and one yellow card to make an equation.
Which blue and yellow card should he choose to give him the equation with

a the largest value for y
b the smallest value for y?
Explain your decisions and show that your answers are correct.

Summary checklist

I can understand equations and solve them.
I can write equations and solve them.

2.6 Inequalities

In this section you will … Key words

• use letters and inequalities to represent open and closed interval
closed intervals.
inequality

You have already learned how to use a letter and an inequality sign integer
to represent lots of numbers.

Remember the inequality signs: Tip
< means ‘is less than’ Remember that
≤ means ‘is less than or equal to’ you use an
> means ‘is greater than’ open circle ( )
≥ means ‘is greater than or equal to’ for the < and >

So if you see the inequality x > 5, this means that x can be any number inequalities and a
greater than 5. closed circle ( )
If you see the inequality y ≤ 2, this means that y can be any number for the ≤ and ≥

less than, or equal to, 2.
inequalities.

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