Question

1.在公式s=1/2（a+b）h,已知s,b,h（h≠ 0）,则a=（ ）

Answer 1

1.

s = (ah+bh)/2

2s - bh = ah

a = (2s - bh) / h

2.

1/y = (1/f1 - 1/f2)

y = 1/((f2-f1)/f1f2)

y = f1f2 / (f2-f1)

3.

a=0.(t ≠ -1)

4.

ax + 2ab = bx + a^2 + b^2

(a-b)x = a^2 - 2ab + b^2

x = (a^2 - 2ab + b^2)/(a-b)

因为

a ≠ b

所以

x = (a - b)^2 / (a - b)

= a -