B. When NaCl (table salt) dissolves in water, the change is endothermic. Yet, when added to water, it dissolves without added energy (spontaneously) over a wide range of temperatures. How can this be? (2 points)
9,18,27,36,45,54,63,72,81,90,99
-84= -4b -4(-7 -8b)
⇒ -84= -4b -4* (-7) -4*(-8b) (distributive property)
⇒ -84= -4b+ 28+ 32b
⇒ -84 -28= 32b -4b
⇒ -112= 28b
⇒ -112/28= b (inverse operation)
⇒ -4= b
Final answer: b= -4
Answer:
option B will he the statement of this equation
Answer: 8
Step by Step:
5/50 = x/80
cross multiply
50x = 400
divide 50 from both sides
x = 8