Răspuns :
[tex]1) \\ \\ \sqrt{360} + \sqrt{40} = 6 \sqrt{10} + 2 \sqrt{10} = 8 \sqrt{10} [/tex]
2)
(2x+5)²=
(2x)²+2•2x•5+5²=
2²x²+2•2x•5+5²=
4x²+2•2x•5+25=
4x²+20x+25
[tex]3) \\ \\ \frac{x}{7} + x + \frac{1}{2} = \frac{9}{7} \\ \\ \frac{8x}{7} + \frac{1}{2} = \frac{9}{7} \\ \\ \frac{8x}{7} = \frac{9}{7} - \frac{1}{2} = \frac{11}{14} \\ \\ 8x = \frac{11}{14} \times 7 = \frac{77}{14}^{(7} = \frac{11}{2} \\ \\ x = \frac{ \frac{11}{2} }{8} = \frac{11}{2 \times 8} = \frac{11}{16} [/tex]
2)
(2x+5)²=
(2x)²+2•2x•5+5²=
2²x²+2•2x•5+5²=
4x²+2•2x•5+25=
4x²+20x+25
[tex]3) \\ \\ \frac{x}{7} + x + \frac{1}{2} = \frac{9}{7} \\ \\ \frac{8x}{7} + \frac{1}{2} = \frac{9}{7} \\ \\ \frac{8x}{7} = \frac{9}{7} - \frac{1}{2} = \frac{11}{14} \\ \\ 8x = \frac{11}{14} \times 7 = \frac{77}{14}^{(7} = \frac{11}{2} \\ \\ x = \frac{ \frac{11}{2} }{8} = \frac{11}{2 \times 8} = \frac{11}{16} [/tex]
1.
√360 + √40 =
√36×√10 + √4×√10 =
6√10 + 2√10 =
8√10
2.
(2x + 5)² =
(2x)² + 2×2x×5 + 5² =
4x² + 20x + 25
3.
x/7 + x + 1/2 = 9/7 /×14
2x + 14x + 7 = 18
16x + 7 = 18
16x = 18 - 7
16x = 11
x = 11/16
x/7 + (x+1)/2 = 9/7 /×14
2x + 7x + 7 = 18
9x = 18 -7
9x = 11
x = 11/9