0.58 x=1,25+0,5
0,58x=1,75
x=1,75/0,58
x=3,02
Sinπ/4=√2/2
cosα=sin(π/2-α)
2×√2/2sin(π/2-(π/4-t))=√2sin(π/2-π/4+t)=√2sin(π/4+t)
1)8 1/3×9=25/3×9=75 ;2)2 2/3×3 1/4=8/3×13/4=26/3 ;3)4 4/7×3 5/24=32/7×77/24=44/3 ;5)75-26/3-44/3=75-(8 2/3+12 2/3)=75-21 1/3=74 3/3-21 1/3=53 2/3