Answer:
Step-by-step explanation:
90x - 60y = 68.....multiply by -1
90x - 70y = 91
---------------------------
-90x + 60y = -68 (result of multiplying by -1)
90x - 70y = 91
---------------------------add
-10y = 23
y = -23/10 <===
90x - 60y = 68
90x - 60(-23/10) = 68
90x + 138 = 68
90x = 68 - 138
90x = - 70
x = -70/90
x = -7/9 <=====
Answer: 120
<u>Step-by-step explanation:</u>
Since the order of the numbers doesn't matter we can use the formula:

X = √7²+4² by using Pythagoras Theory as the triangle is a right angled triangle
Answer:
Experiment
Step-by-step explanation:
Base on the scenario been described in the question, where Mrs. Reynolds has many (over a hundred) houseplants of many different types including philodendrons, ferns, spider plants, cacti, tomatoes, pineapples, this is a typical example of experiment .
An experiment is a procedure carried out to support, refute, or validate a hypothesis. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when a particular factor is manipulated
Answer:1st same 2nd same 3rd diffrent 4 the same
Step-by-step explanation: