My dictionary is not as thick as Jane' s => Jane' s dictionary ......

1) Skiing is easy and riding is easy too => Skiing is as .......

2) Carol is more beautiful than Mary => Mary is not .....

3) His house is bigger than mine => My house is not ......

Các bạn giải hộ mình bài 84 (trang 149) - sbt - toán 7 và giải thích cho mình vì sao lại làm như thế nhé?

Cảm ơn các bạn nhiều!

Cho a+b+c+d khác 0 sao cho: \(\dfrac{b+c+d}{a}=\dfrac{a+c+d}{b}=\dfrac{b+a+d}{c}=\dfrac{c+b+a}{d}\)

Hãy tính: M = \(\dfrac{2a+5b}{3c+4d}-\dfrac{2b+5c}{3d+4a}-\dfrac{2c+5d}{3a+4b}+\dfrac{2d+5a}{3c+4b}\)