..........,....................
<em>Ответ: во вложении Объяснение:</em>
А) 4y-1-2y+7+3y-1 5y+5 5(y+1)
--------------------- = -----------= --------- =
5y 5y 5y
y+1 y 1
----- = ----+ -----= y+1
y y y
л) 2×(a-b)×(a+b) 2a+6b 2×(a-b)
------------------- × -----------= ---------- =
2×(a+3b) b(a+b) b
2a-2b 2a 2b 2a
----------= ------ - ----- = ---- - b
b b b b
<span><span>3<span>x2</span> - 124x - 84 = 0</span>
<span><span>D = (-124)2 - 4·3·(-84)</span> = 16384</span>
<span><span><span>x1 = </span><span>124 - √16384</span> = <span><span>-2</span>3</span></span>2·3</span>
<span><span><span>x2 = </span><span>124 + √16384</span> = 42</span><span>2·3
</span></span></span>