Answer:
x=1 y =15
Step-by-step explanation:
hopefully correct
-5x-2y=13 (i)
3x-y=12
-y=12-3x
y=-12+3x (ii)
substitute ii into i
-5x-2(-12+3x)=13
-5x +24-6x=13
-11x=-11
x=1
substitute x into ii
y=-12+3(1)
y=15
.
. . x=1 and y =15
Answer:
x = 80°
Step-by-step explanation:
Angle on a straight line = 180°
(x + 40)° + (x - 20)° = 180°
x + 40° + x - 20° = 180°
2x + 20° = 180°
2x = 180° - 20°
2x = 160°
x = 160°/2
x = 80°
Check:
(x + 40)° + (x - 20)° = 180°
(80° + 40°) + (80° - 20°) = 180°
120° + 60° = 180°
180° = 180°
Answer:
22 grams
Step-by-step explanation:
loses 50% of it's mass per 22 years
so after 22 years the mass would be 44 grams
22 years later would leave 50% of 44 grams = 22 grams
