x +y = 20 ( rewrite as x = 20-y)
3x - 3y =30
3(20-y) - 3y = 30
60-3y - 3y = 30
60-6y = 30
-6y = -30
y = -30 / -6 = 5
x=20-5 = 15
x = 15, y = 5
Answer:
Instrumental understanding – having a mathematical rule and being able to apply and manipulate it. Relational understanding – having a mathematical rule, knowing how to use it AND knowing why it works.
Step-by-step explanation:
Instrumental understanding involves “memorising which problems a method works for and which not, and also learning a different method for each new class of problems” (Skemp 1987, p. 159), is a desire to know “some kind of rule for getting the answer” (p. 155) so that a student can “latch on it and ignore the rest”
Step-by-step explanation:
Hsjsisusshskakaisussgsgshwuiwiwiwjwhgwywuwoqoajgsgsuwiwow
G>=5, so anything above or equal to 5 would count. So, you could use 5, 6, 7.
25.5
102/4=25.5
Not really sure though
