3)6х²-7х+1=0
Д= 49-4*6*1=49-24=25
х1,2=7±5/12
х1=0,5
х2=1
4)не знаю
<span><span><span>
18−<span>5<span>(<span>+3</span>)</span></span></span>><span>1−<span>7</span></span></span><span><span>18−<span>5<span>(<span>x+3</span>)</span></span></span>><span>1−<span>7x</span></span></span></span><span><span><span><span>18−<span>5</span></span>−15</span>><span>1−<span>7</span></span></span><span><span><span>18−<span>5x</span></span>−15</span>><span>1−<span>7x</span></span></span></span><span><span><span>3−<span>5</span></span>><span>1−<span>7</span></span></span><span><span>3−<span>5x</span></span>><span>1−<span>7x</span></span></span></span><span><span><span><span><span>−5</span></span>+<span>7</span></span>><span>1−3</span></span><span><span><span><span>−5</span>x</span>+<span>7x</span></span>><span>1−3</span></span></span><span><span><span>2</span>><span>−2</span></span><span><span>2x</span>><span>−2</span></span></span>x> - 1 <span><span>>−1
</span></span>
2x^2-18x+36=0
Д=324-4×2×36=36
х1=18+6/4=6
х2=18-6/4=3
Х 2 3 1
у 2 4 0
теперь просто начерти график и расставь точки