30 г ------100%
х -------- 4%
х=(30*4)/100=120/100=1,2 (г)
{x+y/5=2/1|*5
{16x=7x+7y+18
{5x+y=10
{16x-7x=7y+18
{5x+y=10
{9x-7y=18
y=(10-5x)
9x-7*(10-5x)=18
9x-70+35x=18
44x=18+70
44x=88|:44
x=2
J
y=10-5*2
y=10-10
y=0
(2,5*√0,64+1/8)/√256=(2,5*0,8+0,125)/16=2,125/16=0,1328125
1
![S= \int\limits^{3 \pi /4}_{ \pi /3} {sinx} \, dx =-cosx|3 \pi /4- \pi /3= \sqrt{2} /2+1/2](https://tex.z-dn.net/?f=S%3D++%5Cint%5Climits%5E%7B3+++%5Cpi+%2F4%7D_%7B+%5Cpi++%2F3%7D+%7Bsinx%7D+%5C%2C+dx+%3D-cosx%7C3+%5Cpi++%2F4-+%5Cpi++%2F3%3D+%5Csqrt%7B2%7D++%2F2%2B1%2F2)
2
Найдем пределы интегрирования
6x-x²=x+4
x²-5x+4=0
x1+x2=5 U x1*x2=4
x1=1 U x2=4
Фигура ограничена сверху параболой,а снизу прямой
![S= \int\limits^4_1 {(-x^2+5x-4)} \, dx =-x^3/3+5x^2/2-4x|4-1=-64/3+40-](https://tex.z-dn.net/?f=S%3D+%5Cint%5Climits%5E4_1+%7B%28-x%5E2%2B5x-4%29%7D+%5C%2C+dx+%3D-x%5E3%2F3%2B5x%5E2%2F2-4x%7C4-1%3D-64%2F3%2B40-+)
![16+1/3-5/2+4=4,5](https://tex.z-dn.net/?f=16%2B1%2F3-5%2F2%2B4%3D4%2C5)
3
Найдем пределы интегрирования
x³=√x
x³-√x=0
√x(√x^5 -1)=0
x=0 x=1
Фигура ограничена сверху графиком у=√х,а снизу у=х³
![S= \int\limits^1_0 {( \sqrt{x} -x^3)} \, dx =2/3* \sqrt{x^3} -x^4/4|1-0=2/3-1/4=5/12](https://tex.z-dn.net/?f=S%3D+%5Cint%5Climits%5E1_0+%7B%28+%5Csqrt%7Bx%7D+-x%5E3%29%7D+%5C%2C+dx++%3D2%2F3%2A+%5Csqrt%7Bx%5E3%7D++-x%5E4%2F4%7C1-0%3D2%2F3-1%2F4%3D5%2F12)