<PRE><B>Question 1176134</B>
solve: 
-1.4 * 10^-11 + 7 * 10^-12
(write in scientific notation) 

this my work: 

turn -1.4 * 10^-11 into -0.14*10^-12 
-0.14* 10^12 + 7 * 10^-12
(7-0.14)*10^-12
7-0.14=6.86 * 10^12
the answer I got was wrong. What did I do wrong? Also how do I fix it? 
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Nothing to solve, just simplify.
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-1.4 * 10^-11 + 7 * 10^-12
= -14 * 10^-12 + 7 * 10^-12
= -7*10^-12
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