Answer:
Step-by-step explanation:
okay, so here are a few methods you can use.
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1) +
x + 7 = 10 so because this is addition we use the reverse, subtraction. So
x - 7 = 10 - 7 and that equals to 3.
2) -
x - 2 = 10 so because this is subtraction we do the reverse, addition.
x + 2 = 10 + 2 and that equals to 12.
3) x
x times 3 = 21 because this is multiplying we divide.
x/3 = 21/3 and that would be 7.
4) /
x/2 = 10 same as above, reverse is multiplying.
x times 2 = 10 times 2 and thats 20.
GL!