-3(x-7)_>15-7x>x+1/3
4-8+3
If a 15MPa concrete design at 7 days is 10Mpa what is the expected strength at 28 days
141.75÷7
100sin(150) * sin (150-x) = 50sin(120)*sin(120+x)
2(2xy+4y-3)dx+(x+2)^2 dy=0
(D²+2D+1)y=4sin2x
(2 1/5 / 3 2/25)X4 2/5 /(3/1 - 1/5)
5*(13+7-9)-21/3=____
2k²+13k+18
