Question

a,-x + 8 = -17

b, 35 - x = 37

c, -19 -x = -20

d, x - 45 = -17

e, | x+ 3| = 15

g, |x-7| +13 = 25

f, |x-3| -16 = -4

k, 26 -| x+9| = -13

Answer 1

a) -x + 8 = -17

⇔ -x = -17 - 8

⇔ -x = -25

⇔ x = 25

b) 35 - x = 37

⇔ x = 35 - 37

⇔ x = -2

c) -19 - x = -20

⇔ x = -19 + 20

⇔ x = 1

d) x - 45 = -17

⇔ x = -17 + 45

⇔ x = 28

e) |x + 3| = 15

⇔ \(\left[{}\begin{matrix}x+3=15\\x+3=-15\end{matrix}\right.\)

⇔ \(\left[{}\begin{matrix}x=15-3\\x=-15-3\end{matrix}\right.\)

⇔ \(\left[{}\begin{matrix}x=12\\x=-18\end{matrix}\right.\)

f) |x - 3| - 16 = -4

⇔ |x - 3| = -4 + 16

⇔ |x - 3| = 12

⇔ \(\left[{}\begin{matrix}x-3=12\\x-3=-12\end{matrix}\right.\)

⇔ \(\left[{}\begin{matrix}x=12+3\\x=-12+3\end{matrix}\right.\)

⇔ \(\left[{}\begin{matrix}x=15\\x=-9\end{matrix}\right.\)

k) 26 - |x + 9| = -13

⇔ |x + 9| = 26 + 13

⇔ |x + 9| = 39

⇔ \(\left[{}\begin{matrix}x+9=39\\x+9=-39\end{matrix}\right.\)

⇔ \(\left[{}\begin{matrix}x=39-9\\x=-39-9\end{matrix}\right.\)

⇔ \(\left[{}\begin{matrix}x=30\\x=-48\end{matrix}\right.\)

Answer 2

a,-x + 8 = -17

=> -x=-17-8

=> -x=-25

=> x=25

vậy x=25

b, 35 - x = 37

=> x=35-37

=> x=-2

vậy x=-2

c, -19 -x = -20

=> x=-19+20

=> x=1

vậy x=1

d, x - 45 = -17

=> x=-17+45

=> x=28

vậy x=28

e, | x+ 3| = 15

th1 x+3=15

=> x=15-3

=> x=12

th2 x+3=-15

=> x=-15-3

=> x=-18

vậy x=12 hoặc x=-18

g, |x-7| +13 = 25

=> \(\left|x-7\right|=25-13\)

=> \(\left|x-7\right|=12\)

th1 x-7=12

=> x=12+7

=> x=19

th2 x-7=-12

=>x=-12+7

=> x=-5

vậy x=19 hoặc x=-5

các câu sau tt

Answer 3

g) |x - 7| + 13 = 25

⇔ |x - 7| = 25 - 13

⇔ |x - 7| = 12

⇔ \(\left[{}\begin{matrix}x-7=12\\x-7=-12\end{matrix}\right.\)

⇔ \(\left[{}\begin{matrix}x=12+7\\x=-12+7\end{matrix}\right.\)

⇔ \(\left[{}\begin{matrix}x=19\\x=-5\end{matrix}\right.\)