Page 11 - 新思维数学活动用书9 样章

1 Number and calculation

8 Write the answer to each division in index form.
−
5
3
a 12 ÷ 12 − 2 b 5 ÷ 5 2
−
3
4
c 3 ÷ 3 8 d 25 ÷ 25 − 4
Challenge
9 Find the value of x in these equations.
x
2
3
a 2 × 2 = 2 9 b 3 × 3 = 3 − 2
x
x
x
c 5 − 3 × 5 = 5 − 5 d 8 × 8 − 3 = 8
10 Find the value of y in these equations.
4
6
y
2
a 3 ÷ 3 = 3 y b 10 ÷ 10 = 10 2
3
y
y
2
c 14 ÷ 14 = 14 − 4 d 8 ÷ 8 = 8 4
11 y = x + x −1 + x −2
0
Find the value of y when
a x = 1 b x = 2 c x = 3.
12 This table shows powers of 11.
11 2 11 3 11 4 11 5 11 6
121 1331 14 641 161 051 1 771 561
Use the table to work out the following. Do not use a calculator.
a 121 × 14 641 b 1 771 561 ÷ 14 641 c 121 ÷ 161 051
13 Find the value of x in this equation: 2 × 4 = 2 x
2
3