(1) 変化率=(3⋅1+2)−(3⋅(−2)+2)1−(−2)=5+43=3\text{変化率} = \frac{(3 \cdot 1 + 2) - (3 \cdot (-2) + 2)}{1 - (-2)} = \frac{5+4}{3} = 3変化率=1−(−2)(3⋅1+2)−(3⋅(−2)+2)=35+4=3 (2) 変化率=(9+1)−(1+1)3−1=10−22=4\text{変化率} = \frac{(9+1) - (1+1)}{3-1} = \frac{10-2}{2} = 4変化率=3−1(9+1)−(1+1)=210−2=4 (3) 変化率=b3−a3b−a=(b−a)(b2+ab+a2)b−a=b2+ab+a2\text{変化率} = \frac{b^3 - a^3}{b-a} = \frac{(b-a)(b^2+ab+a^2)}{b-a} = b^2 + ab + a^2変化率=b−ab3−a3=b−a(b−a)(b2+ab+a2)=b2+ab+a2 (4) 変化率 ={(a+h)2+2(a+h)−3}−(a2+2a−3)a+h−a=a2+2ah+h2+2a+2h−3−a2−2a+3h=2a+h+2= \frac{\{(a+h)^2+2(a+h)-3\} - (a^2+2a-3)}{a+h-a} = \frac{a^2+2ah+h^2+2a+2h-3-a^2-2a+3}{h} = 2a+h+2=a+h−a{(a+h)2+2(a+h)−3}−(a2+2a−3)=ha2+2ah+h2+2a+2h−3−a2−2a+3=2a+h+2